DATE  DUE 


OBSERVATIONS 


0]S’ 

CERTAIN  PARTS 


OF 


THE  ANIMAL  (ECONOMY, 


INCXUSIVE  OF  SETEHAL  PAPERS  FB03I 

THE  PHILOSOPHICAL  TRANSACTIONS,  ETC. 


BY 

JOHN  HUNTER, 


F.  R.  S. 


^lotes 

BT 

RICHARD  OWEN,  F.R.S., 

Fellow  of  the  Linnean,  Geological,  and  Zoological  Societies  of  London. 
Corresponding  Member  of  the  Royal  Academy  of  Sciences  of  Berlin  ; of  the  Royal  Academy  of 
Medicine  and  Philomathic  Society  of  Paris;  and  of  the  Academy  of  Sciences  of 
Philadelphia,  Moscow,  Erlangen,  &c. 

Professor  of  Anatomy  and  Physiology,  and  Conservator  of  the  Museum  of  the  Royal  College  of 

Surgeons  in  London. 


HASWELL,  BARRINGTON,  AND  HASWELL, 

293  MARKET  STREET. 

NEW  ORLEANS:  JOHN  J.  HASWELL  & CO. 

1840. 


TO 


SIR  JOSEPH  BANKS,  Bart., 

PRESIDENT  OF  THE  ROYAL  SOCIETY,  ETC.,  ETC. 

Dear  Sir, 

As  the  following  Observations  were  made 
in  the  course  of  those  pursuits  in  which  you  have  so  warmly 
interested  yourself,  and  promoted  with  the  most  friendly 
assistance,  I should  be  wanting  in  gratitude  were  I not  to 
address  them  to  you,  as  a public  testimony  of  the  friendship 
and  esteem  with  which  I am. 

Dear  Sir, 

Your  obliged  and 

Very  humble  Servant, 

JOHN  HUNTER. 

Leicester  Square,  Nov.  9,  178G. 


:il053 


4 

Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/observationsonce01hunt 


ADVERTISEMENT 


To  the  First  Edition  of  the  Animal  (Economy,  1786. 


The  nine  following  papers  have  been  read  at  the  Eoyal 
Society,  and  published  in  the  Philosophical  Transactions ; 
but  in  a work  of  so  general  a nature,  and  of  which  physio- 
logical inquiries  make  so  small  a part,  the  few  facts  and 
observations  which  I have  given  upon  such  subjects  may 
probably  be  overlooked  by  those  who  are  not  members  of 
that  Society.  That  they  may  be  more  easily  procured  by 
students  in  medicine,  and  other  readers,  I have,  by  an  ap- 
plication to  the  President  and  Council  of  the  Royal  So- 
ciety, obtained  leave  to  reprint  such  of  them  as  I consider 
to  be  connected  with  the  principles  and  actions  of  the  Ani- 
mal QHconomy;  and  I have  added  such  observations  and 
remarks  as  have  occurred  to  me  since  the  time  they  were 
read  before  the  Royal  Society. 


2 


:il053 


ADVERTISEMENT 


To  the  Second  Edition  of  the  Animal  (Economy,  1792. 


Eleven  of  the  following  papers  have  been  read  at  the 
Royal  Society,  and  published  in  the  Philosophical  Trans- 
actions; but  in  a work  of  so  general  a nature,  and  of  which 
physiological  inquiries  make  so  small  a part,  the  few  facts 
and  observations  which  I have  given  upon  such  subjects 
may,  probably,  be  overlooked  by  those  who  are  not  mem- 
bers of  that  Society.  That  they  may  be  more  easily  pro- 
cured by  students  in  medicine,  and  other  readers,  I have, 
by  an  application  to  the  President  and  Council  of  the 
Royal  Society,  obtained  leave  to  reprint  them,  in  this  work, 
as  being  connected  with  the  principles  and  actions  of  the 
Animal  CEconomy ; and  I have  added  such  observations 
and  remarks  as  have  occurred  to  me  since  the  time  they 
were  read  before  the  Royal  Society. 


PREFACE. 


Always  an  admirer  of  the  genius  of  Hunter,  and  of  late  years 
obliged  by  official  duties  to  make  frequent  reference  to  his  numerous 
and  varied  productions,  especially  to  those  which  ai'e  scattered 
through  different  volumes  of  the  Philosophical  Transactions  and 
other  works,  I have  often  felt  the  inconvenience  that  resulted  from 
the  absence  of  a uniform  edition  of  the  whole  of  the  extant  works 
of  that  great  and  original  thinker.  When,  therefore,  Mr,  Palmer 
first  communicated  to  me  his  design  of  publishing  a new  edition  of 
Hunter’s  wmrks,  I heard  with  peculiar  satisfaction  his  intention  to 
include  in  the  proposed  collection  ev^ery  memoir  of  the  author  that 
could  be  found  in  print,  and  I gladly  lent  my  assistance,  which, 
however,  the  previous  assiduous  researches  of  Mr.  Palmer  rendered 
of  little  moment,  towards  completing  a list  of  all  the  published 
essays  or  observations  on  various  parts  of  the  ‘ Animal  (Economy’ 
which  had  not  before  been  included  in  the  work  so  entitled.  The 
proposal  which  Mr.  Palmer  at  the  same  time  made  to  me  to  edit 
this  portion  of  the  works  of  Hunter  I declined,  from  a sense  of  the 
inadequacy  of  my  powers  to  grapple  with  so  vast  a range  of  im- 
portant physiological  subjects  as  the  contemplated  volume  must 
necessarily  embrace,  and  I sincerely  hoped  that  Mr.  Palmer  would 
have  found  a coadjutor  better  qualified  than  myself  to  do  justice  to 
this  portion  of  his  most  useful  and  praiseworthy  undertaking. 

After  a lapse  of  nearly  two  years  Mr.  Palmer  again  applied 
to  me  to  revise  the  papers  on  the  Animal  (Economy,  and  I then 
acceded  reluctantly  to  his  request,  led,  by  the  sole  motive  of  accele- 
rating the  appearance  of  a much  wished-for  edition,  to  a task,  to 
which  I have  since  dedicated  a great  portion  of  my  leisure  hours, 
without  the  slightest  expectation  of  profit  or  honour,  the  experiment 
having  only  served  to  convince  me  of  the  difficulty  of  adding  the 
observations  demanded  by  the  progress  of  science  to  the  text  of 
Hunter  in  the  spirit  of  its  author,  and  a retrospect  of  my  annota- 
tions leading  me  to  suspect  that  often,  wfith  every  wash  to  avoid  it, 
I may  have  tacitly  implied  an  ignorance  on  the  part  of  Hunter  of 
facts  with  which  he  was  probably  well  acquainted,  and  to  perceive 
that,  in  general,  the  addition  of  such  details  tends  to  overload  and 
destroy  the  force  of  the  original  observations  in  the  text. 

It  is  with  much  more  satisfaction  that  I refer  to  the  additions 
which  have  been  made  to  the  present  edition  of  the  Animal  (Eco- 
nomy of  the  hitherto  uncollected  or  unpublished  writings  of  its 
original  author. 


8 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


These  consist  of  the  following  essays. 

From  the  Philosophical  Transactions : 

“ On  the  Anatomy  of  the  Siren  or  Amphibious  Bipes  (1700).” 
“On  the  Electric  Organs  of  the  Torpedo  (1772).” 

“On  the  Electric  Organs  of  the  Gymnotus  (1755).” 

“ Experiments  and  Observations  on  Vegetables  with  respect  to 
the  power  of  producing  Heat  (1775).” 

“ A case  of  Small-pox  communicated  by  the  Mother  to  the 
Foetus  (1780).” 

“ Anatomical  Remarks  on  a New  Marine  Animal  (1785).” 

“ Observations  on  the  Structure  and  CEconomy  of  Whales 
(1787).” 

“ On  Bees  (1792).” 

“ On  the  Fibrous  Structure  of  the  Crystalline  Lens  (1793).” 

“ On  the  Fossil  Bones  of  the  Caverns  of  Gailenreuth  (1794).” 

“ Six  Croonian  Lectures  read  before  the  Royal  Society  by  Hunter 
in  the  years  1776,  1777,  1779,  1780,  1781,  and  1782,”  but  with- 
drawn from  publication  by  the  Author. 

From  the  Medical  Commentaries  of  Dr.  William  Hunter: 

“ Experiments  on  Absorjition  by  Veins.” 

From  the  Transactions  of  a Society  for  the  Promotion  of  Medical 
and  Chirur^ical  Knowledge,  vol.  ii.  (1794): 

“ Description  of  the  Human  Uterus  and  Ovum  in  the  first  Month 
of  Pregnancy.” 

“Observations  on  the  Growth  of  Bone.” 

There  is  also  added, 

“An  Account  of  the  Anatomy  of  the  Jerboa,”  contributed  by 
Hunter  to  the  Appendix  to  Russel’s  History  of  Aleppo.  And, 
lastly, 

“ Descriptions  of  Five  Marsupial  Quadrupeds,”  from  the  Zoo- 
logical Appendix  to  White’s  Voyage  to  JVew  South  Wales.  (1790.) 

In  order  to  bring  these  different  memoirs  in  juxtaposition  with 
papers  on  analogous  subjects  in  the  original  edition  of  the  Animal 
CEconomy.  a slight  alteration  has  been  made  in  the  arrangement 
of  the  different  essays  composing  that  work.  Those  which  relate 
to  generation  are  brought  together  at  the  beginning  of  the  volume; 
then  follow  the  observations  on  digestion,  animal  heal,  and  other 
physiological  subjects;  and  lastly,  the  papers  of  a descriptive 
character,  which  refer  more  immediately  to  comparative  anatomy 
and  zoology.  Thus  for  the  first  time  are  collected  into  one  volume 
the  physiological  and  anatomical  stores,  from  which,  in  connexion 
with  the  materials  composing  his  museum  or  destined  for  its  illus- 
tration, an  adequate  idea  may  be  formed  of  the  nature  of  the  great 
work  in  which  Hunter  had  purposed  to  record  the  sum  of  his  vast 
experience. 

In  the  year  1786,  when  Hunter  published  a collection  of  his 
detached  memoirs  in  the  first  edition  of  the  Animal  CEconomy,  he 


PREFACE. 


9 


observes,  with  reference  to  the  subject  of  digestion,  “ I cannot  at 
present  spare  sufficient  time  to  give  my  opinions  at  large  on  this 
subject,  with  all  the  experiments  and  observations  I have  made 
upon  it,  but  as  soon  as  I have  leisure  I shall  lay  them  before  the 
public.”  And  again,  in  describing  the  organ  of  hearing  in  fishes, 
he  premises  that  he  reserves  a more  complete  investigation  of  this 
part  of  natural  history  “ for  a larger  work  on  the  structure  of 
animals,  which  I one  day  hope  to  have  it  in  my  power  to  publish,” 
and  he  states  that  ever  since  the  year  1760  his  researches  have 
been  continued  in  every  part  of  the  animal  ceconomy.  Hence 
instead  of  regarding  the  uncommon  structures  which  he  discovered 
in  his  dissections  of  different  animals  as  individual  peculiarities,  he 
was  enabled  to  advance  beyond  the  anatomists  of  his  own  times, 
and  view  them  from  the  same  eminence  to  which  subsequent 
induction  has  raised  the  observers  of  the  present  day;  and  referring 
to  the  series  of  preparations  in  his  museum,  he  boldly  states  with 
reference  to  the  structure  of  the  organ  of  hearing  in  fish,  that  it  is 
“ only  a link  in  the  chain  of  varieties  displayed  in  the  formation  of 
this  organ  of  sense  in  different  animals,  descending  from  the  most 
perfect  to  the  most  imperfect  in  a regular  progression.” 

The  importance  of  these  views,  and  tiie  nature  and  amount  of 
the  knowledge  which  they  indicated,  could  not  be  appreciated  by 
the  contemporaries  of  Hunter  in  the  absence  of  a detailed  exposi- 
tion of  the  evidences  on  which  they  wmre  founded.  It  is  no  w'onder, 
therefore,  that  we  find  his  earlier  eulogists  sometimes  founding  his 
claims  to  scientific  eminence  on  insecure  grounds;  some,  for 
example,  lauding  him  as  the  author  of  a theory  of  the  organizing 
energy,  which  may  be  traced  to  the  time  of  Aristotle,  or  as  the 
originator  of  the  doctrine  of  the  vitality  of  the  blood,  which  is 
supported  with  so  much  eloquence  by  Harvey  and  his  immediate 
successors;  while  others,  taking  more  definite  grounds,  have  often 
unfortunately  selected  as  his  discoveries  precisely  those  subjects  of 
Hunter’s  special  researches  in  which  he  had  but  revived  and  ex- 
tended the  ideas  of  his  predecessors.  Of  this  we  have  a striking 
example  in  the  introductory  observations  on  the  character  of  Hun- 
ter contained  in  Sir  Everard  Home’s  Lectures  on  Comparative 
Anatomy,  vol.  i.,  p.  6,  in  which  the  independent  function  of  the 
vesiculae  seminales  and  the  determination  of  the  organ  of  hearing 
in  fishes  are  adduced  as  Hunterian  discoveries. 

The  true  originators  of  these  and  of  other  ideas  and  facts  which 
Hunter  may  have  regarded  as  his  discoveries,  and  which  he  doubtless 
did  discover  so  far  as  independent  and  original  research  constitutes 
a claim  to  that  honour,  I have  been  careful  to  point  out  in  every 
case  where  my  reading  has  led  me  to  detect  in  an  older  author  a 
clear  anticipation  of  Hunter. 

It  cannot  be  doubted,  however,  that  the  ascription  to  Hunter  byr 
his  friends  and  admirers,  of  facts  and  opinions  to  which  he  had  no 
title  as  the  original  discoverer,  must  have  contributed  to  lower  his 
character  in  the  estimation  of  continental  anatoinists ; whose 


10 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


acquaintance  with  the  vast  accumulation  of  facts  in  comparative 
anatomy  due  to  the  labours  of  the  numerous  cultivators  of  that  sci- 
ence in  the  sixteenth  and  seventeenth  centuries,  easily  enabled  them 
to  detect  the  weakness  of  such  claims,  without  perhaps  their  possess- 
ing such  a knowledge  of  Hunter’s  labours  as  to  justly  appreciate 
their  scope  and  tendency,  and  to  view  them,  as  they  deserve  to  be 
viewed,  in  the  light  of  a first  great  attempt  to  arrange  in  one  con- 
catenated system  the  diversified  facts  in  comparative  anatomy. 

Cuvier,  for  example,  in  his  review  of  the  progress  of  science  in 
the  latter  half  of  the  eighteenth  century,  a period  which  may  be  re- 
garded as  a second  revival  of  comparative  anatomy  and  physiology, 
places  Hunter  in  an  inferior  category  of  contributors  to  those  sciences. 
After  eulogizing  the  share  wliich  the  erudite  Haller  took  in  demon- 
strating the  importance  of  comparative  anatomy  to  the  advance- 
ment of  physiology,  and  the  corresponding  effects  which  the  labours 
ofDaubenton  and  Pallas  produced  in  establishing  sounder  ideas  of 
the  classification  of  animals,  the  historian  of  the  natural  sciences 
goes  on  to  state  : “John  Hunter  in  England,  the  two  Monrosin 
Scotland,  Camper  in  Holland,  and  Vicf|  D’Azyr  in  France,  were 
the  first  who  followed  their  footsteps.  Camper,”  he  observes,  “ cast, 
so  to  say,  a passing  glance  of  the  eye  of  genius  on  a number  of  in- 
teresting objects,  yet  almost  all  his  labours  were  but  sketches. 
Vicq  D’Azyr,  wdth  more  assiduity,  was  arrested  by  a premature 
death  in  the  midst  of  a brilliant  career;  but  their  works  inspired  a 
general  interest,  which  has  ever  since  been  on  the  increase.” 

With  reference  to  the  nature  or  influence  of  the  labours  of  Hunter, 
Cuvier  is  silent ; he  limits  himself  to  an  indication  in  a marginal 
note  of  the  Treatise  on  the  Teeth  and  “ les  autres  ecrits  de  Hunter 
inseres  en  partie  dans  les  Transactions  P/ii/osophiquesT* 

This  was  meting  out  but  scanty  justice  to  the  author  of  the 
Treatise  on  the  Blood  and  of  the  Observations  on  the  Animal 
QHconomy,  which  abound  with  so  many  general  propositions  in 
comparative  anatomy  and  physiology.  If,  how'ever,  this  opinion 
of  Cuvier  be  excusable  under  the  circumstances  under  wdneh  it 
was  written,  it  would  be  unpardonable  not  to  appeal  against  it  upon 
the  evidence  of  the  higher  claims  of  Hunter  aflbrded  by  the  present 
edition  of  his  works  and  by  those  manuscripts  which  have  already 
appeared  in  the  catalogue  of  his  Physiological  collection  published 
by  the  Royal  College  of  Surgeons.  Had  these  manuscripts,  expla- 
natory of  the  design  of  the  Hunterian  collection,  been  published 
before  Cuvier  wrote  the  work  from  which  we  have  just  quoted, 
that  astonishing  result  of  Hunter’s  labours  might  perhaps  have 
claimed  a passing  notice  from  one  w'hose  statements  all  Europe 
now  receives  and  all  posterity  will  regard  with  confidence  and 
respect. 

“ Les  autres  ecrits,”  the  “ other  writings”  of  Hunter  to  which 
Cuvier  alludes,  are  indeed  devoted  rather  to  the  development  of 

* Histoire  des  Progres  des  Sciences  Naturelles,  depuis  1789,  tom.  i.,  p.  302 


PREFACE. 


11 


general  principles  in  physiology  than  to  the  detail  of  the  anatomical 
observations  upon  which  he  founded  them.  Many  of  the  facts 
ascertained  in  the  course  of  his  higher  and  more  comprehensive 
inquiries,  and  incidentally  alluded  to  in  the  narration,  are  however 
fully  as  interesting  and  important  as  those  which  other  anatomists 
have  sometimes  thought  worthy  of  being  made  the  subjects  of 
express  monographs. 

But  Hunter  had  higher  aims  than  the  reputation  of  a mere  col- 
lector of  facts  in  comparative  anatomy  ; and  this  he  not  only  felt 
but  had  expressed  in  an  early  period  of  his  career.  In  a manu- 
script, copied  by  Mr.  Clift,  relating  to  a dissection  of  a turtle,  he 
says,  “ The  late  Sir  John  Pringle,  knowing  of  this  dissection,  often 
desired  me  to  collect  all  my  dissections  of  this  animal,  and  send 
them  to  the  Royal  Society  ; but  the  publishing  of  a description  of  a 
single  animal,  more  especially  a common  one,  has  never  been  my 
wish.” 

Howsoever  we  may  regret  this  feeling,  which  has  undoubtedly 
deprived  the  world  of  the  results  of  much  inestimable  labour,  and 
has  operated  in  various  ways  disadvantageously  to  Hunter’s  own 
reputation,  yet  it  indicates  the  expanded  views  of  the  man  who  en- 
tertained it. 

Had  Hunter  published  seriatim  his  notes  of  the  structures  of  the 
animals  which  he  dissected,  these  contributions  to  comparative 
anatomy  would  not  only  have  vied  with  the  labours  of  Daubenton  as 
recorded  in  the  Histoire  JVaturelle  of  Buflbn,  or  with  the  Compara- 
tive Dissections  of  Vicq  d’Azyr  which  are  inserted  in  the  early 
volumes  of  the  EncydopMie  Methodique  and  in  the  Memoires  de 
V Acadtmie  Royah  de  France,  but  they  would  have  exceeded  them 
both  together. 

It  would  be  tedious  to  enumerate,  name  by  name,  the  different 
species  of  animals  whose  organization  was  investigated  and  recorded 
by  Hunter.  Mr.  Clift  has  evidence*  that  he  left  written  descrip- 
tions, from  autopsy,  of  the  anatomy  of  the  following  Mammalia: 


Of  Quadrumana 

. 21  Species. 

Carnivora  . 

51 

Rodentia 

20 

Edentata 

5 

Ruminantia  . 

15 

Pachydermata 

10 

Cetacea 

6 

Marsupiata  . 

10 

Of  Birds  . 

. 84  Species. 

Reptiles 

25 

Fishes 

19 

Of  Insects . 

, 29  Species. 

Of  other  invertebrate  animals,  as  mollusca,  red-blooded  worms, 
and  radiata,  upwards  of  twenty.  From  the  titles  of  manuscripts, 

♦ See  “ Evidence  before  the  Medical  Committee  of  the  House  of  Commons.” 


12 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


therefore,  it  appears  that  Hunter  possessed,  at  the  period  of  his 
decease,  original  records  of  the  dissections  of  three  hundred  and 
fifteen  different  species  of  animals. 

In  addition  to  these.  Hunter’s  preparations  testify  that  he  had 
dissected  twenty-three  species  of  mammalia,  sixteen  species  of  birds, 
fourteen  species  of  reptiles,  forty  species  of  fishes,  forty-two  difierent 
mollusca,  and  about  sixty  species  of  articulate  and  radiate  animals; 
all  species  of  animals  of  whose  anatomy  we  have  no  evidence  that 
he  left  written  descriptions.  So  that  by  adding  these  undescribed 
dissections  to  those  of  winch  we  derive  the  evidence  from  the  list 
of  the  manuscripts,  and  of  which  described  dissections  his  anatomi- 
cal collection  in  like  manner  contains  evidences  in  the  dissected 
and  preserved  organs,  there  is  proof  that  Hunter  anatomized  at 
least  five  hundred  dill'erent  species  of  animals,  exclusive  of  repeated 
dissections  of  difierent  individuals  of  the  same  species,  besides  the 
dissections  of  plants  to  a considerable  amount. 

With  respect  to  the  rarer  and  less  known  invertebrate  animals. 
Hunter  was  not  content  with  merely  recording  their  structure  and 
displaying  its  leading  peculiarities  in  preparations  ; but  he  caused 
most  elaborate  and  accurate  drawings  to  bo  made  from  the  recent 
dissections  ; for  which  purpose  he  retained  in  his  family  many  years 
an  accomplislied  draughtsman,  Mr.  William  Bell,  better  known  as 
the  author  of  two  papers  in  the  Philosophical  Transactions,  de- 
scriptive of  the  Sumatran  Rhinoceros  and  the  Ecan  Bonna  (Platax 
arthriticus,  Cuv.).  Several  examples  of  these  beautiful  designs  have 
already  been  published  by  the  Council  of  the  Royal  College  of  Sur- 
geons in  the  illustrated  catalogue  of  the  Hunterian  Museum  : they 
relate  to  the  anatomy  of  the  Sepia  and  Solen,  of  the  Ascidia  and 
Salpa;  the}^  illustrate  the  circulation  of  the  blood  in  the  Crustacea 
and  Anellida  ; and  the  figure  which  Mr.  Hunter  has  given  of  the 
circulation  in  the  Chloeia  capillata,  a red-blooded  worm,  far  sur- 
passes in  beauty  and  detail  any  of  tiiose  with  which  Cuvier  illus- 
trates the  memoir*  dedicated  to  what  he  regarded  to  his  latest 
breath  as  one  of  his  most  interesting  discoveries. 

Hunter  had  also  minutely  investigated  the  anatomy  of  the  cir- 
ripeds  ;t  but  of  his  dissections  of  these,  as  of  many  other  animals, 
it  is  to  be  lamented  that  the  preparations  and  drawings  are  now  the 
sole  evidences.  The  illustrations  of  the  anatomy  of  the  Echinoder- 
mata,  both  of  the  spiny  species  and  of  the  unarmed  Holothuria, 
have  never  been  surpassed  either  as  to  minuteness  or  accuracy  ; 
and,  excepting  the  disputed  article  of  the  nervous  system,  little  is 
added  in  the  elaborate  and  well-known  monograph  of  'I'iedemann, 
to  the  anatomy  of  the  Holothuria  as  it  is  displayed  by  Hunter.J 

Now  the  anatomical  labours  of  Daubenton  were  confined  to  that 
class  of  animals  whose  structure  most  nearly  resembles  man;  he 

* Bulletin  de  la  Soc.  Philomath.,  1791,  p.  146. 

f See  Physiological  Catalogue  of  the  Hunterian  Collection,  vol.  i.,  p.  255, 
plJlV. 

t Ibid.,  p.  251,  pi.  III. 


PREFACE. 


13 


describes  the  position  and  length  and  breadth  and  number  of  parts 
with  most  praiseworthy  zoological  precision,  but  never  appears  to 
raise  his  thoughts  to  the  relations  of  the  structures  he  detected  with 
the  habits  of  the  species,  or  their  adaptation  to  function.  Hence 
he  has  been  said  to  have  made  more  discoveries  of  which  he  was 
unconscious  than  any  other  cultivator  of  comparative  anatomy. 

Vicq  d’Azyr,  on  the  contrary,  adorns  his  descriptions  with  many 
beautiful  and  philosophical  views,  but  he  did  not  carry  his  scalpel 
beyond  the  vertebrate  series  ; while  Hunter  explored  every  modi- 
fication of  animal  structure,  fi’om  man  down  to  the  polype. 

If  Hunter  surpassed  his  contemporaries  in  the  value  and  amount 
of  the  materials  wdiich  he  collected  in  comparative  anatomy,  he 
rises  far  above  them  in  the  application  of  his  facts. 

By  a profound  and  unremitting  meditation  on  the  diversities  of 
structure  presented  to  his  view,  he  derived  more  accurate  notions 
than  were  current  amongst  his  contemporaries  of  the  parts  essen- 
tial to  the  performance  of  the  different  functions,  and  every  idea  or 
doubt  thus  suggested  he  tested  by  the  most  varied,  ingenious,  and 
accurate  experiments. 

“Many  things,”  he  observes,  “ arise  out  of  investigation  which 
were  not  at  first  conceived  ; and  even  misfortunes  in  experiments 
have  brought  things  to  our  knowledge  that  were  not,  and  probably 
could  not  have  been,  previously  conceived.  On  the  other  hand,  I 
have  often  devised  experiments  by  the  fireside  or  in  my  carriage, 
and  have  also  conceived  the  result ; but  when  I tried  the  experi- 
ment the  result  was  different,  or  I found  the  experiment  could  not 
be  attended  with  all  the  circumstances  that  were  sucrorested.”* 

OO 

Few  physiologists  indeed,  if  any,  have  made  more  numerous,  va- 
rious and  conclusive  experiments  than  Hunter.  Yet  he  says,  “ I 
think  it  ma^  oe  set  dowm  as  an  axiom  that  experiments  should  not 
be  often  repeated  which  merely  tend  to  establish  a principle  already 
known  and  admitted,  but  that  the  next  step  should  be  the  applica- 
tion of  that  principle  to  useful  purposes.”! 

By  this  series  of  labours  of  mind  and  hand,  prosecuted  uninter- 
ruptedly from  year  to  year.  Hunter  at  length  came  to  establish  a 
body  of  physiological  doctrines,  to  the  happy  influence  of  which 
on  the  treatment  of  the  various  “ ills  that  flesh  is  heir  to,”  every 
cultivator  of  the  healing  science  now  bears  grateful  testimony. 

Most  of  the  enlightened  physiologists  of  this  country  have  ac- 
knowledged the  high  merit  and  beneficial  influence  of  Hunter’s 
labours;  but  the  general  terms  in  wdiich  his  merits  have  been  ex- 
pressed have  not  availed  in  raising  him  from  the  secondary  cate- 
gory of  contributors  to  comparative  anatomy,  in  w?hich  he  has  been 
classed  by  Cuvier,  and  from  which  some  continental  writers  have 
lately  been  disposed  to  degrade  him.J 

* Animal  (Economy,  p.  417  (the  pages  throughout  refer  to  the  present  edition). 

f Ibid.,  p.  1 17. 

! .See  the  Esquisse  Ilistorique  sur  VAnaiomie  Comparee,  prefixed  to  the  French 
translation  of  the  second  edition  of  Carus’s  Comparative  Anatomy,  vol.  i.,  p.  xxx. 


14 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  present  seems,  therefore,  to  be  a fitting  opportunity  to 
attempt  to  define  the  grounds  for  assigning  a higher  station  to 
Hunter,  considered  as  a phj'siologist  and  comparative  anatomist. 
In  this  endeavour,  however,  to  prove  what  Hunter  was  as  a dis- 
coverer, we  must  also  fairly  state  what  he  was  not. 

He  has  been  spoken  of  as  the  originator  of  the  idea  of  a subtle 
imponderable  principle  operating  in  the  fluids  and  solids  of  the 
organism,  and  causing  the  phrenomena  of  life.  But  such  a prin- 
ciple, under  various  names  and  with  various  attributes,  has  been 
assigned  as  the  cause  of  organization  by  Aristotle,  Harvey,  Willis, 
Cudworth,  Grew',  Van  Ilelmont,  and  Stahl. 

As  both  Harvey  and  Hunter  had  spent  laborious  lives  in  earnest 
inquiries  and  repeated  dissections  and  experiments,  to  ascertain 
relations  between  structure  and  function ; as  both  had  studied  the 
changes  which  take  place  in  the  form  and  structure  of  animals 
from  their  embryo  state  to  that  of  maturity  ; and  as  both  had  care- 
fully traced  the  successive  phaenomena  which  occur  in  the  egg 
during  incubation, — the  similarity  of  their  opinions  on  the  nature 
and  powers  of  the  vital  principle  is  correspondingly  close. 

Both  arrived  at  the  conclusion,  that  an  animating  principle  exists 
and  operates  in  the  ovum  prior  to  the  formation  of  any  organ  of 
the  future  animal.  Both  attributed  the  power  by  which  the  fecund 
egg  resists  putrefaction,  while  the  unprolific  one  decomposes,  to  a 
principle  of  life,  which  Harvey  more  precisely  terms  the  “ anima 
vegetiva.”* 

Hunter,  however,  carries  his  researches  a step  further;  he  sub- 
mits the  fecund  egg  to  a low  temperature,  and  ascertains  a new 
property,  of  which  Harvey  was  ignorant,  a powmr,  viz.,  of  resist- 
ing cold  : he  also  shows  that  when  once  frozen,  and  killed  by  cold, 
the  dead  impregnated  egg  yields  to  putrefaction  like  the  unimpreg- 
nated one. 

Both  physiologists  observed  that  if  the  phsenomena  of  a vital 
principle  were  manifested  in  one  part  of  the  organization  more  than 
in  another,  it  was  in  the  blood.  “For  the  blood,”  says  Harvey, 
“ is  the  first  formed,  and  is  the  primary  animate  particle  of  the  em- 
bryo; it  is  generated  prior  to  the  punctum  saliens,  before  the  first 
rudiment  of  the  heart,  and  is  endowed  with  the  vital  heat  or  princi- 
ple before  it  begins  to  move,  and  from  it  does  pulsation  commence. 


* “ Plurimum  itaque  mecum  ipse  rep\Uavi,  qiii  fieret,  ut  ova  improlifica  gal- 
linae  supposita,  ab  eodem  calore  extraneo  corrumpanlur,  "putrescant,  et  foetida 
evadant;  ovis  autem  foecundis  idem  non  contingat.”  Ha.T'/eii  De  Generatione 
Animalium  ExercUatio  22. 

“Ovum  itaque  est  corpus  naturale  virtute  animali  preeditum  ; principio  nempe 
motus,  transmutationis,  quietis,  et  conservationis.”  Exercit,  26. 

“ Cum  enim  in  ovo  macula  prius  dilatetur,  colliquamentum  concoquatur  et 
praeparetur,  pluriniaque  alia  (non  sine  providentia)  ad  pulli  formationem  et  in- 
crementum  instituanlur,  antequam  quidpiam  pulli  vet  ipsa  primogenita  ejus 
particula  appareat;  quidni  utique  credamus  calorem  innatum  animamque  pulli 
vegetativara  ante  pullum  ipsum  exsistere  !”  Exercit,  57. 


PREFACE. 


l.'i 


For  the  thing  containing  is  made  to  be  serviceable  to  the  thing  con- 
tained. 

“ Nor  is  the  blood  therefore  to  be  call  the  primogenial  part,  be- 
cause that  in  and  from  it  the  organ  of  pulsation  is  derived,  but  also 
because  the  animal  heat  and  vital  principle  are  first  implanted 
therein;  and  in  it  does  life  consist.  For  where  heat  and  motion 
first  begin,  there  also  life  doth  first  arise  and  last  expire.  ” — Harvey, 
On  Generation,  pp.  274,  275. 

This  explicit  and  beautiful  enunciation  of  the  preexistence  of  the 
blood  to  the  machine  by  which  it  is  mainly  circulated,  and  of  its 
endowment  of  life,  fell  barren  from  the  pen  of  Harvey  (if  we  except 
the  brief  practice  of  transfusion  to  which  it  gave  rise),  and  was  for- 
gotten, when  Hunter  resumed  the  inquiry.  And  why,  it  may  be 
asked,  was  the  doctrine  of  the  vitality  of  the  blood  inoperative,  as 
taught  by  Harvey?  Because  instead  of  establishing  that  doctrine 
by  observations  and  experiments,  from  which  alone  it  was  suscep- 
tible of  deriving  further  proof, — instead  of  applying  the  principle  to 
the  explanation  of  the  phaenomena  of  disease,  and  to  a modification 
and  improvement  of  remedial  measures,  Harvey  obscures  and  for- 
gets the  conclusion  of  his  cooler  moments  of  observation,  and,  as 
the  learned  Barclay  well  observes,  excited  by  the  discovery  which 
had  extended  his  fame  so  widely  over  Europe,  and  had  reflected 
such  lustre  on  his  name  and  country,  he  expatiates  on  the  blood 
as  something  divine  ; he  has  recourse  to  hyperbole,  and  describes 
its  properties  in  the  extravagant  language  of  romance. 

Hunter,  on  the  contrary,  carries  a series  of  calm  and  philosophi- 
cal investigations  on  the  vital  properties  of  the  blood  to  an  extent 
which  has  never  been  surpassed  ; he  examines  it  under  every  con- 
dition, both  in  the  vessels  and  out  of  the  vessels,  during  circulation 
and  at  rest,  in  health  and  in  disease.  He  aims  to  establish  the 
period  in  its  formation  at  which  it  manifests  the  vital  properties  ; 
and  he  fully  details  the  changes  which  it  undergoes,  and  the  phreno- 
nrena  which  supervene  in  the  rest  of  the  or’ganism  when  these  pro- 
perties are  lost.  Lastly,  he  tells  us  how  the  blood,  by  means  of  its 
vital  properties,  assists  in  the  restorati-on  of  parts  when  injured  or 
diseased. 

Hunter  subjects  the  blood  to  both  mechanical  and  chemical  analy- 
sis, and  endeavours  to  determine  the  characteristic  properties  of  its  dif- 
ferent constituents.  It  was  not  known  in  his  time  upon  which  of 
these  constituents  the  act  of  coagulation  depended.  Hunter  took 
advantage  of  a case  in  which  the  red  globules  subsided,  as  in  some 
cases  they  do,  more  rapidly  than  usual,  and  skimming  oft'  the  super- 
incumbent colourless  fluid,  found  that  the  fibrin,  as  it  is  now  termed, 
immediately  coagulated  and  formed  a colourless  clot.*  A subse- 
quent erroneous  theory,  which  attributed  the  act  of  coagulation  to 
the  red  globules,  has  recently  been  set  aside  by  the  application  of 
an  ingenious  process  for  artificially  separating  the  fibrin  from  the 


* Treatise  on  the  Blood,  &c.,  p.  32. 


IG 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


blood  disks  before  coagulation  takes  place,  and  the  opinions  of 
Hunter  on  this  point  have  been  fully  established  by  the  experiments 
of  Muller.  With  respect  to  the  serum,  Hunter  instituted  a number 
ot  experiments  and  made  many  ingenious  observations  to  determine 
the  relative  quantity  of  the  coagulable  to  the  uncoagulable  part. 
His  deductions  as  to  the  amount  of  nutrient  albumen  in  the  blood 
of  animals  of  different  ages,  and  under  different  circumstances,  as  re- 
gards exercise  or  rest,  &c.,  formed,  from  observing  the  quantity  of 
gravy  or  uncoagulable  serosity  which  d ifferent  roasted  meats  afforded, 
is  highly  characteristic  of  hisoriginal  and  ever  active  mind.  In  seek- 
ing to  determine  the  respective  importance  of  the  different  constitu- 
ents of  the  blood,  by  the  philosophical  and  most  difficult  inquiry  into 
their  respective  periods  of  foi’mation  in  the  development  of  the 
embryo.  Hunter  made  the  interesting  discovery  that  the  vessels  of 
the  embryo  of  a red-blooded  animal  circulated  in  the  first  instance 
colourless  blood,  as  in  the  invertebrate  animals. 

“ The  red  globules,”  he  observes,  “seem  to  be  formed  later  in 
life  than  the  other  two  constituents,  for  we  see  while  the  chicdv  is 
in  the  egg  the  heart  beating,  and  it  then  contains  a transparent  fluid 
before  any  red  globules  are  formed,  which  fluid  we  may  suppose  to 
be  the  serum  and  the  lymph.”* 

I well  remember  the  feelings  of  surprise  with  which  I listened 
while  at  Paris  in  1832  to  a memoir  read  before  the  Academy  of 
Sciences  by  MM.  Delpech  and  Coste,  the  object  of  which  was  the 
announcement  of  the  same  fact  as  a novel  and  important  discovery. 
The  statement  of  the  French  observers  was  received  with  all  the 
consideration  which  its  importance  justly  merited,  without  its  being 
suspected  that  our  great  physiologist  had  half  a century  before  em- 
braced it,  with  all  its  legitimate  deduction,  in  the  extended  circle 
of  his  investicrations. 

o 

In  the  same  spirit  in  which  he  investigated  the  nature  of  the  blood 
he  also  pursued  his  researches  on  the  properties  of  the  solids;  he 
endeavours  to  determine  the  specific  powers  and  vital  phsenomena 
of  the  nervous  system  and  of  the  stomach  ; he  compares  these  im- 
portant parts  of  the  animal  body,  with  reference  to  the  degree  of 
energy  with  which  their  functions  are  manifested  ; he  considers  the 
influence  which  they  reciprocally  exert  in  maintaining  the  vitality 
of  the  blood,  and  the  relative  dependence  of  the  whole  organism  on 
the  integrity  of  their  vital  powers.  He  also  dwells  at  great  length 
on  tile  sympathies  resulting  from  these  mutual  relations  and  de- 
pendencies. 

In  all  his  physiological  researches  we  may  see  that  instead  of 
dogmatising  on  the  powers  and  virtues  of  an  abstract  essence, 
Hunter  endeavours  to  analyse  the  vital  forces  peculiar  to  each 
organic  element,  and  to  classify,  as  it  were,  the  phsenomena  of  which 
life  consists. 

If  we  turn  from  Hunter’s  researches  on  life  to  his  investigations 

* Treatise  on  the  Blood,  &c.,  p.  71. 


PREFACE. 


17 


on  another  equally  difficult  and  recondite  subject  in  general  physio- 
logy, viz.,  Animal,  or  rather.  Organic  Heat,  we  see  the  same  exer- 
cise of  the  powers  of  the  same  great  and  original  mind. 

He  first  determines  the  relative  extent  to  which  the  power  of 
generating  heat  or  resisting  cold  is  enjoyed  in  the  two  grand  divi- 
sions of  organic  nature,  plants  and  animals  : he  next  investigates  the 
degree  in  which  that  power  is  possessed  by  different  classes  of 
animals;  then  the  relation  subsisting  between  that  degree  and  the 
perfection  and  complexity  of  the  organization  with  which  the  power 
is  associated.  He  anticipates  some  modern  physiologists  in  determin- 
ing the  different  power  of  generating  heat  manifested  by  the  same 
species  at  different  periods  of  life,  and  advances  a step  further  by 
considering  the  different  powers  of  resisting  cold  which  different 
parts  of  the  same  organized  body  possess  in  relation  to  their  re- 
spective ages  and  periods  of  formation.*  He  lastly  analyses,  so  to 
say,  the  different  functions,  to  determine  in  what  degree  the  pro- 
duction of  heat  depends  on  their  exercise;  and  reciprocally,  the  in- 
fluence of  the  temperature  of  the  body  upon  the  active  and  healthy 
maintenance  of  their  function. 

Throughout  all  this  beautiful  and  justly  celebrated  inquiry  we  see 
the  philosopher  conscious  of  the  extent  of  his  powers,  and  of  the 
kind  of  knowledge  which  the  right  exercise  of  those  powers  was 
adapted  to  acquire.  We  now  here  perceive  a trace  of  a desire  to 
establish  a theory  of  the  nature  of  animal  heal  in  the  abstract. 

Let  any  one  compare  the  language  of  Harvey  or  of  Willis,  while 
expatiating  on  the  caliduminnaLum,  with  the  following  just  remark: 
“ I shall  not,”  says  Hunter,  “ attempt  to  settle  whether  heat  is  a 
body  or  matter,  or  only  a property  of  matter,  which  appears  to  me 
to  be  merely  a difference  in  terms,  for  a property  must  belong  to 
something. ”f 

It  is  precisely  in  the  same  spirit  that  he  conducts  his  researches 
on  life  ; and  I would  say,  after  a very  careful  study  of  the  writings 
of  Hunter,  that  of  all  physiologists  he  is  one  to  whom  a dogmatic 
theory  of  abstract  life  can  least  be  attributed.  But  by  those  whose 
notions  of  Hunter’s  doctrines  are  founded  solely  on  a perusal  of  the 
posthumous  “ Treatise  on  the  Blood”  he  is  liable  to  be  misconceived, 
and  in  opinions  expressed  from  that  limited  acquaintance  with  his 
writings  to  be  misrepresented. 

With  the  just  ideas  w'hich  Hunter  had  acquired  of  the  laws 
of  vitality  and  organic  heat  he  was  enabled  to  explain  many  of 
the  phrenomena  of  digestion  more  satisfactorily  than  had  been 
done  by  his  predecessors  Spallanzani  and  Reaumur. 

The  following  is  a fair  example  of  the  different  views  and 
Kinds  of  knowledge  which  these  experiments  brought  to  the 
inquiry. 

Spallanzani  had  observed  that  digestion  did  not  go  on  in  rep- 
tiles below  a certain  temperature,  he  thought  therefore  that  heat 


♦ P.  158. 


3 


t P.  162. 


IS 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


was  necessary  to  assist  in  the  dissolving  processes  of  the  sto- 
mach ; Hunter,  referring  to  the  same  fact,  shows  that  the 
influence  here  is  not  merely  chemical,  but  that  the  heat  operates 
by  first  raising  the  sensitive  powers,  these  then  transmit  the 
stimulus  to  the  respiratory  and  circulating  functions,  and  lastly  to 
the  motive  and  other  actions  and  faculties,  and  that  the  digestive 
organs  are  necessarily  excited  to  corresponding  actions,  in  order  to 
supply  the  waste  occasioned  by  the  working  of  the  machine,  which 
the  heat  has  thus  called  into  play. 

Hunter  more  accurately  determined,  and  first  applied  and  render- 
ed fruitful  the  fact  which  Grew  incidentally  mentions,  viz.,  That  it 
is  the  property  of  a living  body  or  part  to  resist  the  action  of  the 
gastric  juice  : and  his  celebrated  paper  ‘-On  the  Digestion  of  the 
Stomach  after  Death,"  is  a beautiful  example  of  the  application  of 
his  general  view  in  physiology  to  the  explanation  of  particular 
phaenomena. 

Of  all  his  published  writing,  the  paper  on  Digestion  convey 
perhaps  the  best  idea  of  the  extent  of  Hunter’s  researches  in  Com- 
parative Anatomy,  and  of  the  soundness  of  his  reasonings  in  General 
Physiology. 

Hunter's  claims  to  the  originality  of  observations  which  have 
been  reproduced  as  new  by  late  physiologists,  I have  pointed  out  in 
the  notes  to  these  and  other  memoirs  ; and  have  particularly  endea- 
voured to  define  the  merit  of  Hunter  as  a discoverer  in  reference  to 
the  absorbent  system. 

Hunter’s  published  writings  on  the  Nervous  System  bear  but  a 
small  proportion  to  the  extent  of  his  anatomical  investigations  on 
this  subject,  especially  as  they  are  manifested  in  the  philosophical 
series  of  preparations  in  the  Gallery  of  his  collection,  in  which  the 
nervous  system  is  traced  through  its  progressive  stages  of  compli- 
cation, from  the  simple  filaments  of  the  entozoon  and  echinoderm, 
to  the  aggregated  masses  which  distinguish  the  organization  of 
man.  The  fibrous  structure  of  the  brain,  the  discovery  of  which, 
though  due  to  Goiter  as  early  as  1 573,  has  sometimes  been  attributed 
to  Reil  and  Gall,  is  displayed  by  Hunter  in  preparations  made  to 
show  the  fact  (Nos.  1335,  1336),  and  is  expressly  mentioned  in  the 
description  of  the  Anatomy  of  the  Whale  Tribe.’^ 

In  treating  of  the  comparative  anatomy  of  the  nervous  system  in 
his  introductory  observations  to  this  division  of  his  Collection,! 
Hunter  rises  to  the  following  generalizations.  He  divides  the  ani- 
mals which  have  brains,  or  visible  aggregations  of  the  nervous  sub- 
stance, into  six  classes,  each  characterized  by  a peculiar  modifi- 
cation of  the  brain. 

The  ‘ f.rst  class'  has  a brain  in  the  form  of  a ring,  through  which 
passes  the  oesophagus,  and  from  which  the  nerves  arise,  like  radii 
from  a centre.  It  consists  of  a pulpy  substance,  somewhat  trans- 
parent, which  is  easily  squeezed  out  when  the  brain  is  cut  into.  It 


P.  373. 


T Physiological  Catalogue,  vol.  iii.,  p.  4. 


PREFACE. 


19 


is  not  enclosed  in  hard  parts,  and  is  not  defended  from  pressure  or 
injuries  more  than  any  other  internal  part. 

The  examples  of  this  type  in  his  Museum  are  selected  from  the 
gastropodous  class  of  Mollusca.  The  same  condition  of  the  nervous 
system  w'e  now  know,  from  the  researches  of  Cuvier,  to  charac- 
terize the  whole  of  a vast  division  of  invertebrate  animals,  including, 
amongst  the  highest  organized  of  that  division,  certain  species, — 
the  dibranchiate  Cephalopods, — in  which  the  character,  as  expressed 
by  Hunter,  is  affected  by  the  development  of  a cartilaginous  cranium 
for  the  protection  of  the  cerebral  ring  ; but  ulterior  researches  have 
not  led  to  any  modification  of  Hunter’s  description  of  the  typical 
form  of  the  brain  in  the  Molluscous  sub-kingdom. 

In  the  ‘ second  class  ^ the  brain  lies  in  the  head  of  the  animals  ; 
it  IS  a pulpy  substance,  somewhat  transparent,  which  giv'es  it  a 
bluish  cast;  from  its  lower  part  go  out  two  large  nerves,  one  passes 
on  each  side  of  the  oesophagus,  and  they  then  unite  into  one,  form- 
ing a knot  at  their  union;  they  disunite  again,  and  so  unite  and 
disunite  alternately  through  the  whole  length  of  the  animal,  at  every 
union  giving  off  the  nerves  as  from  the  brain.  This  structure. 
Hunter  says,  he  suspects  to  answer  both  the  use  of  a medulla  spinalis 
and  the  great  intercostal  nerve. 

The  examples  of  the  class  of  animals  adduced  by  Hunter  as 
being  characterized  by  this  essential  form  of  the  nervous  system 
are  the  leech,  earthworm,  aphrodita,  centipede,  caterpillar,  scorpion, 
and  lobster.  Subsequent  researches  have  shown  that  it  exists  in 
the  barnacles,  or  Cirripedia,  which  most  zoologists  now  rank  in  the 
same  primary  division  with  the  Anellides,  Insects,  Arachnidans,  and 
Crustaceans. 

In  the  first  class  of  animals  in  this  neurological  arrangement  (for 
in  enunciating  general  propositions  respecting  any  given  organ  the 
comparative  anatomist  becomes  involuntarily,  as  it  were,  a classi- 
ficator  of  animals  as  well  as  organs).  Hunter  observes,  “ we  had 
the  brain  surrounded  by  soft  parts  only.  In  the  second  it  was 
closely  surrounded  by  soft  parts,  but  these  were  surrounded  by 
hard.  In  the  ^ third  class’  the  brain  has  a case  of  hard  parts  for 
itself,  called  the  skull.” 

Now  when  Hunter  made  a brain  relatively  larger  than  in  his 
first  two  classes — protected  by  a skull, — and  continuous  with  a 
medulla  spinalis  extended  down  the  back,  and  an  endowment  of 
the  five  senses, — the  essential  neurological  characters  of  his  third 
class  of  animals, — he  erred  in  not  applying  them  to  his  fourth,  fifth, 
and  sixth  classes,  as  an  attribute  common  to  all,  and  one  which  dis- 
tinguished each  alike  from  the  two  lower  classes.  The  apprecia- 
tion of  the  great  natural  group  characterized  by  a brain  and  spinal 
chord,  situated  on  the  dorsal  aspect  of  the  body,  and  protected  by 
a vertebral  case,  was  reserved  for  the  sagacious  penetration  of 
Cuvier. 

However,  in  so  far  as  Hunter  limits  his  generalizations  to  the 
brain  alone,  he  is  consistent  with  himself,  and  exact  in  the  differential 


20 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


characters  which  he  points  out.  The  brain  in  fish,  for  example,  or 
his  ‘ third  class,’  is  a very  irregular  iDass,  inconstant  in  its  form  and 
in  the  number  of  its  parts  ; still  the  “ several  parts  which  are  similar 
to  those  in  a superior  class  may  be  picked  out;”  the  skull,  more- 
over, is  too  large  for  the  brain,  and  the  interspace  is  filled  by  a 
cellular  membrane,  which  Hunter  compares  to  the  arachnoid. 

In  the  ‘ fourth  class,’  the  parts  composing  the  brain  “ do  not  lie 
one  upon  another,  but  are  very  much  detached  and  follow  one 
another,”  in  short,  are  cliaracterized  by  their  linear  arrangement; 
a character,  the  accuracy  of  which,  as  applied  to  the  Reptilia,  has 
been  confirmed  by  all  subsequent  experience.  It  is  interesting  to 
observe  how  Hunter  determines  the  nature  of  these  diflerent  de- 
tached masses.  He  says,  “ The  two  anterior  consist  of  the  cere- 
brum ; the  two  middle,  I should  suppose,  of  the  nates  and  testes, 
which  I take  to  be  the  middle  lobes  detached,  because  in  the  bird 
they  are  more  underneath,  not  so  much  between  the  cerebrum  and 
cerebellum  ; the  posterior  is  the  cerebellum,  consisting  of  one  body 
entirely.”*  Every  eminence.  Hunter  further  observes,  has  a cavity 
or  ventricle  in  it.  The  linear  arrangement  of  the  masses  of  the 
brain  is  common  both  to  fishes  and  reptiles;  but  the  relation  of 
those  masses  to  the  skull,  and  their  variable  number  and  propor- 
tions, according  to  Hunter,  distinguish  the  brain  in  fish.  He  further 
observes  that  in  the  crocodile  the  parts  of  the  brain  are  more  closely 
connected,  and  that  the  skull  is  more  in  contact  with  it,  in  which 
respect  it  comes  nearer  the  bird  than  do  any  of  the  other  amphibia. 

The  brain  in  the  ‘ ffth  class’  or  fowl.  Hunter  characterizes  by 
its  greater  relative  size,  and  the  superposition  of  its  component 
masses. 

In  the  ‘ sixth  class’  or  quadrupeds,  the  brain  is  in  general  larger 
than  in  the  preceding,  and  the  parts  more  compacted,  the  whole 
mass  being  brought  into  nearly  a globular  figure.  “ The  nates  and 
testes  are  four  small  bodies,  with  no  visible  cavities;  are  not  seen 
externally,  but  lie  at  the  posterior  end  of  the  third  ventricle.”! 

In  the  observations  printed  in  the  present  volume  on  the  branches 
of  the  fifth  pair  which  are  distributed  to  the  nose  and  ear,  we  can- 
not fail  to  observe  that  Hunter  had  entered  on  that  track  of  inquiry, 
and  perceived  the  governing  principle  or  idea,  which,  more  clearly 
appreciated  and  steadily  retained  by  Sir  Charles  Bell,  has  since  led 
to  such  important  improvements  in  this  department  of  physiology. 

Hunter  premises  his  description  of  the  nerves  which  supply  the 
organ  of  smelling  by  calling  attention  to  the  constancy  which  per- 
vades the  anatomical  conditions  of  the  nerves,  and  states  in  general 
his  belief  that  particular  nerves  have  particular  functions,  in  relation 
to  their  differences  of  origin,  union,  and  distribution  ;J  but  this 
simple  enunciation,  without  the  proofs  and  illustrations  of  which  it 
was  susceptible,  became  unproductive  of  its  proper  results,  and 
appears  to  have  been  subsequently  lost  sight  of  by  Hunter  himself, 

* Physiological  Catalogue,  vol.  iii.,  p.  7.  f Ibid.,  p.  10. 

f Pp.  204,  205. 


PREFACE. 


21 


when  speculating  on  the  nerves  as  internuntiate  conductors  of  a 
materia  vitae  diffusa. 

A knowledge  of  Hunter’s  opinions  on  the  nervous  system,  derived 
only  from  the  observations  on  that  subject  which  occur  in  the 
Treatise  on  the  Blood,  might  lead  to  the  belief  that  he  attributed  to 
all  the  different  nerves  one  common  function  ; but  after  perusing 
the  distinct  exposition  of  his  views  on  this  branch  of  physiology  as 
recorded  in  the  Animal  fficonomy,  it  appears  to  me  that  Hunter 
needed  only  to  have  resorted  to  experiment  in  this,  as  he  did  so 
successfully  in  other  fields  of  physiological  inquiry,  to  have  esta- 
blished the  nature  and  degree  of  the  functional  differences  of  these 
nerves,  of  which  he  describes  the  anatomical  conditions  giving  rise, 
as  he  sufjposes,  to  those  differences. 

He  limits  himself,  however,  in  his  illustration  of  the  grand  propo- 
sition, by  anatomical  examples  only.  He  shows  that  organs  like 
the  eye  and  nose,  which  are  endowed  by  means  of  one  nerve  with 
a special  sense,  derive  their  ordinary  sensation  from  a second  nerve 
having  a different  origin.  This  nerve  he  determines,  in  the  case 
of  the  eye  and  nose,  to  be  the  fifth  pair.  He  says  the  same  mode 
of  reasoning  is  equally  applicable  to  the  organ  of  taste,  and  he  traces 
the  corresponding  superadded  nerve  to  the  ear. 

Hunter  further  distinguishes  the  sensations  of  the  stomach  and  of 
the  glans  penis  as  being  peculiar,  and  shows  that  as  these  peculiar 
sensations  reside  in  particular  nerves,  so  at  whatever  part  of  the 
nerve  the  impression  is  made  it  always  gives  the  same  sensation  as 
if  affected  at  the  common  seat  of  the  sensation  of  that  peculiar 
nerve. 

In  another  place  Hunter  makes  the  ingenious  remark  that  the 
nerves  which  are  specially  designed  to  receive  peculiar  impressions 
convey  the  ideas  of  such  impressions  to  the  brain,  in  whatever  way 
they  may  be  affected  or  stimulated.  Thus  he  says,  “ A mechanical 
impression  on  the  retina  produces  an  impression  of  light  ; a blow 
on  the  ear  the  sensation  of  sound.”*  And  later  experiments  have 
only  extended  this  principle,  by  showing  that  whether  the  nerve  be 
affected  by  mechanical,  chemical,  or  electrical  stimuli,  it  conveys 
the  same  sensation. 

Much  importance  has  been  attributed  to  these  observations,  on 
the  supposition  that  they  were  new,  and  I have  been  induced  to 
dwell  thus  long  upon  Hunter’s  contributions  to  the  physiology  of 
the  nervous  system,  because  in  most  of  the  recent  works  upon  that 
subject  he  does  not  receive  the  credit  which  is  due  to  him  for 
having  made  them. 

The  physiological  discoveries  of  Bell,  Magendie,  Mayo,  and 
Muller,  have  resulted  from  the  combination  of  experiment  with  a 
philosophical  consideration  of  the  anatomical  peculiarities  of  the 
nervous  system.  It  was  the  neglect  of  experiment  in  this  depart- 
ment of  physiology  which  rendered  Hunter  unable  to  account  for 

•Lectures  on  Surgery,  p.  56-7,  of  the  present  edition, and  Parkinson’s  Hun- 
terian Reminiscences,  p.  12. 


3* 


22 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


the  peculiarities  which  equally  struck  his  mind  as  being  connected 
in  an  intimate  degree  with  the  functions  of  the  nerves. 

Had  Hunter  combined  experiment  with  dissection  when  he  traced 
the  lateral  branch  of  the  nervus  vagus  in  the  cod,  the  eel,  and  the 
gymnotus,  and  wondered  “ that  a nerve  should  arise  from  the  brain 
to  be  lost  in  common  parts,  while  there  was  a medulla  spinalis 
giving  nerves  to  the  same  parts,'’  this  probably  would  not  have 
remained  to  him,  as  he  expresses  it,  “ one  of  the  inexplicable  cir- 
cumstances of  the  nervous  system.”* 

Having  been  induced  to  dwell  on  the  improved  views  which 
Hunter  either  established  or  suggested  in  different  branches  of 
physiology,  I proceed  next  to  advance  a few  instances  of  his  dis- 
coveries in  comparative  anatomy,  which,  on  the  supposition  that 
they  were  original,  have  contributed  to  add  to  the  reputation  of 
subsequent  anatomists. 

1.  The  oi'gan  of  hearing  in  the  sepia.  The  fact  that  this  cepha- 
lopod  possesses  the  organ  in  question  is  stated  at  p.  300  of  the 
present  edition  of  the  Animal  CEconomy,  and  it  is  said  to  differ 
from  that  of  fishes.  The  discovery  is  attributed  by  Cuvier  to 
Scarpa. 

2.  The  semicircular  canals  of  the  Cetacea,  described  by  Hunter 
in  the  paper  on  whales,  a structure  which  Cuvier  rightly  states 
that  Camper  overlooked,  but  incorrectly  claims  the  discovery  as 
his  own. 

3.  In  the  latest  sketch  of  the  history  of  comparative  anatomy, 
prefixed  to  the  French  translation  of  Carus’s  Zootomie,  John  Hunter 
is  introduced  as  the  impudent  self-approprialor  of  Camper’s  dis- 
covery of  the  air-cells  in  the  bones  of  birds;  and  the  historian  of 
the  science  does  not  honour  him  with  any  further  notice. 

Now  the  facts  with  reference  to  this  subject  are  as  follows : 
Camper’s  account  of  the  air-cells  in  the  bones  of  Birds  was  first 
published  in  the  Dutch  language  in  the  year  1774,  the  same  year  in 
which  Mr.  Hunter’s  discovery  was  published  in  the  Philosophical 
Transactions.  The  French  memoir  of  Camper  was  not  published 
till  the  year  1776,  in  the  seventh  volume  of  the  Memoh'es  Etrang. 
de  V Academie  de.s  Sciences  de  Paris.  Hunter  gives  the  date  of  his 
discovery  as  being  in  1758;  Camper  his,  in  the  year  1771. 

The  numerous  observations  and  experiments  which  their  respec- 
tive memoii’s  detail  are  not  such  as  could  hastily  be  got  up  for  an 
unworthy  purpose  ; but  as  both  memoirs  (w'hich  differ  materially  in 
their  general  scope  and  tlie  mode  in  which  the  subject  is  treated) 
W'ere  published  in  the  same  year,  the  lionour  of  tlie  discovery  may 
fairly  be  attributed  to  both  their  authors. 

J might  dwell  on  the  philosophical  comparison  which  Hunter 
makes  between  the  abdominal  air-cells  of  the  bird  and  those  of 
reptiles  and  fishes  had  he  not  in  this  instance  been  anticipated  by 
Harvey.  Harvey,  however,  was  not  aware  that  the  respiratory 


Animal  CEconomy,  p.  412-13. 


PREFACE. 


23 


system  was  extended  into  the  muscular  interstices  and  the  cavities 
of  the  bones ; the  honour  of  which  discovery  must  be  assigned  to 
Hunter  and  Camper,  without  the  necessity  of  supposing  that  either 
had  borrowed  from  the  other. 

The  preparations  in  the  Hunterian  Collection  and  the  Manuscript 
Catalogues  show  that  Mr.  Hunter  had  discovered  the  peritoneal 
canals  or  openings  in  the  eel,  salmon,  and  the  cartilaginous  fishes, 
in  the  crocodile,  and  the  continuation  of  the  same  peritoneal  canals 
into  the  corpus  cavernosum  penis  in  the  tortoise  and  turtle.  The 
latter  have  been  recently  rediscovered  by  MM.  Isidore  St.  Hilaire 
and  Martin  St.  Ange. 

Hunter’s  printed  works,  preparations,  manuscripts  and  drawings 
contain  proofs  of  his  discovery  of  the  circulation  of  the  blood  in 
insects,  and  of  the  peculiar  diffused  irregular  and  extended  venous 
receptacles  in  these  and  the  crustaceous  animals,  in  the  latter  of 
which  their  existence  remains  unnoticed,  even  in  the  latest  works 
on  the  subject. 

In  the  Treatise  on  the  Blood*  we  have  an  opportunity  of  judging, 
by  the  accuracy  of  the  general  propositions  which  he  enumerates 
on  this  subject,  of  the  extent  of  Hunter’s  researches  on  the  com- 
parative anatomy  of  the  circulating  system,  and  of  the  spirit  in 
which  he  prosecuted  the  induction  of  particular  facts.  I cannot 
resist  the  quotation  of  the  following  passages  which  relate  to  the 
circulation  in  insects.  “ In  the  winged  insects  which  have  but  one 
heart,  as  also  but  one  circulation,  there  is  this  heart  answering  both 
purposes”  (viz.,  the  corporeal  and  the  pulmonary  circulations), 
p.  172. 

“ Many  of  those  which  have  one  ventricle  only  have  no  auricle, 
such  as  insects;  but  there  are  others  which  have  both  a ventricle 
and  auricle,  such  as  fish,  the  snail,  and  many  shell-fish  ; some  of 
the  last  class  have  indeed  two  auricles,  with  only  one  ventricle. — ” 

The  heart  “ is  placed  in  what  is  called  the  chest  in  the  quadruped, 
bird,  amphibia,  fish,  and  the  aquatic  and  terrestrial  insect,  but  not 
in  what  may  be  called  the  chest  in  the  flying  insect. 

“ The  chest  in  the  aquatic  insect  seems  best  suited  to  contain  the 
lungs  and  branchiaj,  and  therefore  the  heart  is  placed  there;  but  as 
the  lungs  of  the  flying  insect  are  placed  through  the  whole  body 
of  the  heart  is  more  diffused,  extending  through  the  whole  length  of 
the  animal.”  p.  174. 

“ Where  the  veins  entering  into  the  heart  are  small  in  comparison 
to  the  quantity  of  blood  which  is  wanted  in  the  ventricles,  then  we 
have  an  auricle  ; but  when  the  veins  near  to  the  heart  are  large, 
there  is  no  auricle,  as  in  the  lobster  and  generally  in  insects.”  p.  176, 

“ In  all  animals  which  have  an  auricle  and  a ventricle,  so  far  as 
I know,  there  is  a bag  (unattached)  in  which  they  are  placed,  called 
a pericardium  ; but  the  insect  tribe,  whether  aerial,  aquatic,  or  ter- 
restrial, have  none,  their  hearts  being  attached  to  the  surrounding 
parts  by  the  cellular  membrane  or  some  other  mode  of  attachment. 


* § 5.,  p.  171  of  the  present  edition. 


24 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  heart  “ gives  to  the  blood  its  motion  in  most  animals,  and 
in  all  it  sends  the  blood  to  the  organs  of  respiration  ; in  the  flying 
insect  it  sends  the  blood  both  to  those  organs  and  to  the  body  at 
large,  but  in  fish  to  those  organs  only',  the  body  at  large  in  them 
having  no  heart.  In  the  amphibia  there  is  an  attempt  towards  a 
heart  both  for  the  lungs  and  body,  but  not  two  distinct  hearts.  In 
the  bird  and  quadruped  there  is  a distinct  heart  for  each.”  And 
again,  “ With  respect  to  its  use,  it  is  in  the  most  simple  kind  of  heart 
to  propel  the  blood  through  the  body  immediately  from  the  veins, 
which  blood  is  to  receive  its  purification  in  this  passage  when  the 
lungs  are  disposed  throughout  the  body  as  in  the  flying  insect.”  p.  179. 

The  researches  of  Cuvier  led  him  to  conceive  that  there  was 
a generally  diflused,  but  passive,  or  non-circulated  condition  of  the 
blood,  coexisting  in  insects  wdth  the  distribution  of  the  breathing 
organs  through  the  whole  body.  Hunter,  on  the  contrary,  while 
he  rightly  appreciated  that  condition  of  the  circulating  system  in 
insects  which  related  to  their  peetdiar  respiration,  viz.,  that  the 
venous  blood  was  diffused  apparently  through  the  cellular  membrane, 
in  the  interstices  of  the  fat,  air-cells,  and  muscles,  and  that  the  veins 
in  insects  might  be  called  in  some  measure  the  cellular  membrane 
of  the  parts  C yet  he  well  knew  the  relations  of  these  diffused  re- 
ceptacles of  the  venous  blood  to  the  dorsal  heart,  and  the  circulatory 
movement  which  w’as  impressed  upon  the  vital  fluid  by  that  organ. 
It  is  this  remarkable  error  of  Cuvier,  with  reference  to  the  circula- 
tion in  insects,  that  has  given  to  the  direct  observations  of  the 
blood’s  motion  by  means  of  the  microscope  in  the  hands  of  Carus, 
Bowerbank,  and  other  excellent  observers,  the  character  of  a new 
discovery. 

Hunter  first  determined  the  bi-auricular  structure  of  the  heart  in 
the  batrachian  caducibranchiate  reptiles,  which  he  included  in  the 
class  Tricoilia  of  his  classification  of  animals  according  to  the 
structure  of  the  heart. 

Hunter  first  discovered,  by  means  of  retrograde  injections  of  the 
tubuli  uriniferi,  that  these  essential  partsof  the  kidney  extended  to 
the  superficies  of  that  gland,  and  were  not  confined  to  the  medullary 
substance.  Meckel,  who  saw  while  in  London  the  beautiful  pre- 
parations establishing  this  fact  (Nos.  1202,1203,  1214,  1215,  1235), 
described  them  on  his  return  to  Germany  to  Mullerj-j-  who,  in  his 
recent  elaborate  work  on  the  glands,  acknowledges  how  important 
this  observation  was  in  establishing  true  notions  of  the  structure 
of  glands. 

H unter  extended  his  researches  on  the  renal  organ  to  the  inver- 
tebrate classes,  and  shows  “ the  kidney  of  the  snail;”  and  the  cor- 
rectness of  this  ascription  to  the  so-called  mucous  gland  has  been 
recently  established  by  the  observations  of  Professors  Jacobson  and 
de  Blainville. 

^ See  Physiological  Catalogue,  ii.,  p.  31  ; also  the  note  at  p.  221,  vol.  iii.,  of 
the  present  edition. 

f De  penitiori  structura  Glasdularum,  fol.  p.  95. 


PREFACE. 


25 


I have  selected  a few  facts  from  amongst  the  multitude  which 
Hunter  ascertained  in  the  progress  of  those  investigations,  by  which 
he  sought  in  the  simpler  modifications  of  the  structures  in  the  lower 
aniaials  the  true  uses  of  the  diflerent  organs  which  are  combined  to 
form  the  complex  frame  of  man. 

I miglit  lastly  allude  to  the  extraordinary  nature  and  extent  of 
Hunter’s  labours  in  another  track  of  physiological  inquiry,  viz.,  that 
which  unfolds  the  law's  of  generation  and  animal  development  ; but 
as  the  work  confided  to  me  by  the  Council  of  the  Royal  College 
of  Surgeons,  viz.,  the  description  of  the  series  of  preparations  on 
these  subjects,  which  include  nearly  one-half  of  Hunter’s  grand 
Physiological  Collection,  is  still  in  progress,  I defer  the  comparison 
of  Hunler’s  labours  in  this  field  wdlh  those  of  his  contemporaries 
until  the  whole  body  of  the  evidence  of  his  discoveries  can  be  laid 
before  the  public. 

The  papers,  however,  wdiich  Hunter  published  in  his  lifetime,  and 
which  form  the  first  part  of  the  present  volume,  convey  a most 
favourable  idea  of  his  views  respecting  this  recondite  branch  of 
physiology.  It  is  here  that  we  find  an  attempt  to  explain  congeni- 
tal defects  by  reference  to  the  transitory  structures  or  metamorpho- 
ses of  foetal  life. 

It  was  a question  in  the  time  of  Hunter  how  it  happened  that  the 
gut  in  the  hernia  congenita  came  to  be  in  contact  with  the  testes. 
Hunter  solved  the  question,  by  directing  attention  to  the  position 
of  the  testis  in  the  abdomen,  and  to  its  relations  to  the  other  abdomi- 
nal viscera,  and  to  the  peritoneum,  a few'  months,  before  the  expi- 
ration of  the  term  of  foetal  development.  He  watched  the  progress 
of  the  gland  to  tlie  scrotum  ; saw  it  carrying  along  with  it  a perito- 
neal pouch  like  the  sac  of  an  intestine,  and  thus  demonstrated,  that 
if  the  closure  of  that  sac  was  prevented  by  the  contemporaneous 
passage  of  a loop  of  intestine,  it  must  remain  a common  receptacle, 
both  of  the  part  which  had  naturally,  and  the  part  wdiich  had  pre- 
lernaturally,  escaped  from  the  abdomen. 

Hunter  then  goes  on  to  show  how  the  early  and  transitory  con- 
dition of  the  tunica  vaginalis  in  the  human  foetus,  and  also  the  still 
earlier  abdominal  position  of  the  testes,  are  permanent  structures  in 
the  low'er  mammalia. 

With  respect  to  monstrosities  in  general.  Hunter  had  drawn  out 
a scheme  for  their  classification,  and  had  produced  them  by  experi- 
ment. In  the  “ Account  of  an  extraordinary  Pheasant”  he  states 
that  every  species  of  animal,  and  every  part  of  an  animal  body,  is 
subject  to  congenital  malformation  ; but  he  knew  that  such  appear- 
ances were  not  attributable  to  a freak  of  Nature,  or  a matter  of 
mere  chance ; for  he  observes  that  every  species  has  a disposition 
to  deviate  from  Nature  in  a manner  peculiar  to  itself.  It  is  this 
principle  which  forms  the  basis  of  the  latest  and  most  elaborate 
treatise  on  monsters,*  a work  which  its  author  describes  as  being 

* Histoire  des  Anomalies  de  I’Org-anization  eliez  I’Homme  et  les  Animaux,  ou 
Traite  de  Teratologie,  par  Isid.  Geotfroy  St.  Hilaire:  Paris,  8vo.  1832. 


26 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


“the  result  of  his  having  established  by  a great  number  of  re- 
searches, that  monsters  are,  like  the  beings  called  normal,  subject 
to  constant  rules.” 

With  respect  to  the  cause  or  origin  of  monsters.  Hunter  referred 
it  to  a condition  of  the  original  germ,  or,  as  he  expresses  it,  “ each 
part  of  each  species  seems  to  have  its  monstrous  form  originally 
impressed  upon  it.”  In  the  introductory  observations  to  his  exten- 
sive collection  of  malformed  foetuses  and  parts,  he  assigns  the 
grounds  for  this  hypothesis,  and  at  the  same  time  enunciates  one  of 
the  most  remarkable  laws  of  aberrant  formations.  “I  should 
imagine,”  he  writes,  “ that  monsters  were  formed  monsters  from 
their  very  first  formation,  for  this  reason,  that  all  supernumerary 
parts  are  joined  to  their  similar  parts,  as  a head  to  a head,  &c.,  &c.” 
In  proof  of  the  important  general  principles,  at  a knowledge  of 
which  Hunter  had  arrived,  I have  elsewhere  quoted  this  passage, 
together  with  the  following  remarkable  one  from  Hunter’s  descrip- 
tions of  his  drawings  illustrative  of  the  development  of  the  chick. 
“ If  we  were  capable  of  following  the  progress  of  increase  of  the 
number  of  the  parts  of  the  most  perfect  animal,  as  they  first  formed 
in  succession  from  the  very  first,  to  its  state  of  full  perfection,  we 
should  probably  be  able  to  compare  it  with  some  one  of  the  incom- 
plete animals  themselves,  of  every  order  of  animals  in  the  creation, 
being  at  no  stage  diflerent  from  some  of  those  inferior  orders;  or 
in  other  words,  if  we  were  to  take  a series  of  animals  from  the 
more  imperfect  to  the  perfect,  we  should  probably  find  an  imperfect 
animal  corresponding  with  some  stage  of  the  most  perfect.”* 

We  may,  I think,  perceive,  from  the  evident  difficulty  with  which 
Hunter  expresses  the  idea,  that  his  mind  w’as  oppressed  with  both 
its  novelty  and  vastness.  Men’s  thoughts  require  to  be  familiar- 
ized with  propositions  of  such  generality  before  their  exact  limits 
and  full  application  can  be  appreciated. 

Sufficient,  however,  has  been  adduced  to  prove  the  tendency  of 
Hunter’s  labours,  and  that  he  possessed  the  highest  qualifications 
as  an  investigator  of  Nature  ; unwearied  in  induction,  sagacious  in 
grouping  together  analogous  phsenomena,  and  ever  striving  to 
ascend  from  propositions  of  less  to  those  of  greater  generality. 

Had  the  means  and  time  been  granted  to  Hunter  to  have  made 
public  the  results  of  all  his  labours,  or  had  his  manuscripts  enuncia- 
ting, or  indicative  of,  so  many  general  principles  been  fairly  appre- 
ciated and  given  to  the  world,  our  teachers  of  anatomy  would  not 
now,  after  a lapse  of  half  a century,  have  but  begun  to  explain  to 
their  students  those  beautiful  laws  of  animal  development,  for  the 
know’ledge  of  which  they  are  indebted  to  the  labours  of  the  profes- 
sors in  the  noble  schools  of  physiology  in  Continental  Europe,  where 
-the  spirit  of  Hunterian  inquiries  seems  to  have  so  long  exclusively 
resided.  But  the  period  which  has  elapsed  before  those  general 
laws  began  to  be  appreciated  in  the  country  where  they  were  first 
detected,  affords,  perhaps,  one  of  the  strongest  indications  of  the 
great  advance  which  Hunter  had  made  in  physiological  science. 

* See  preface  to  the  Physiological  Catalogue,  vol.  i.  p.,  ii. 


PREFACE. 


27 


It  would  be  a strange  exception  to  the  usual  result  of  an  exten- 
sive knowledge  of  comparative  anatomy,  combined  with  a tendency 
to  express  in  general  propositions  new  physiological  and  structural 
truths,  if  the  possession  and  application  of  that  knowledge  with  that 
tendency  had  so  led  to  some  corresponding  advance  towards  a 
natural  system  of  zoological  classification.  Accordingly  we  find 
the  contemporaries  of  Hunter  ascribing  to  him  the  highest  ac- 
complishment which  the  zoologist  can  aspire  to,  that  of  discerning 
the  natural  affinities  of  a nondescript  object;  and  this  in  terms  and 
on  occasions  which  seem  to  imply  a general  admission  of  his  pos- 
session of  such  attainments.  When  the  rare  quadrupeds  of  Austra- 
lia were  first  brought  to  England,  presenting,  as  they  did,  to  the 
eye  of  the  zoologist  anomalies  and  peculiarities  not  less  striking  than 
those  which  perplexed  the  botantist  in  the  plants  from  the  same  part 
of  the  world,  it  was  to  Hunter  that  they  were  referred. 

“ There  was  no  person,”  says  Dr.  Shaw,  “ to  whom  they  could 
be  given  with  so  much  propriety,  he  perhaps  being  most  capable  of 
examining  accurately  their  structure,  and  making  out  their  place  in 
the  scale  of  animals.”* 

It  may  not  be  uninteresting  to  contrast  the  sketches  of  systems 
of  zoological  arrangement  which  Hunter  has  left,  with  the  Linnrean 
method  which  prevailed  in  his  time,  and  which  continued  to  prevail 
until  superseded  by  the  labours  of  Cuvier,  specially  and  unremit- 
tingly directed  to  that  end.  We  have  already  seen  that  Hunter’s 
attempts  to  enunciate  general  propositions  respecting  the  nervous 
system  led  him  to  detect  the  condition  characteristic  of  the  mol- 
luscous sub-kingdom,  and  to  speak  of  the  animals  with  “ the  brain 
in  the  form  of  a ring,  ” &c.,  as  a class.  In  still  more  definite  terms 
he  describes  the  condition  of  the  nervous  system  which  characterizes 
the  articulate  Invertebrata. 

With  respect  to  that  higher  type  of  the  nervous  sj^stem,  which 
is  manifested  in  its  aggregation  into  spinal  and  cerebral  masses, 
we  have  seen  that  Hunter  alludes  to  it  as  distinguishing  only  the 
class  of  fishes  from  his  first  and  second  classes,  or  the  Molluscous 
and  Articulate  divisions  as  they  are  now  termed  ; and  that  he  failed 
to  perceive  that  all  the  other  vertebrate  classes  were  equally  charac- 
terized by  it.  To  Hunter,  however,  we  must  award  the  merit  of 
having  first  obtained  a perception  of  the  distinct  group  formed  by 
the  higher  organized  vermes  of  Linnaeus,  and  their  essential  organ- 
ical  character.  Hunter  had  also  investigated  the  structure  of 
zoophytes,  in  which  no  annular  brain  can  be  detected  ; he  had 
conceived  the  idea  of  animals  in  which  the  nervous  matter,  or 
something  analogous  to  it,  a materia  vitce  diffusa,  was  dispersed 
throughout  the  system.  And  we  find  another  learned  contem- 
porary of  Hunter,  in  ascribing  a diffused  condition  of  the  nervous 
matter  to  the  Taenire,  bearing  testimony  that  Hunter  had  entertained 

* Zoological  Appendix  to  White’s  Voyage  to  New  South  Wales,  p.  463  of 
the  present  work. 


28 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


a similar  opinion,  and  had  applied  that  character  of  the  nervous 
system  to  many  of  the  lovi'er  tribes  of  animals.* 

The  distribution  of  animals  according  to  the  nervous  element  of 
their  organization,  is,  however,  but  one  of  several  attempts  at  classi- 
fication which  Hunter  made.  The  next  scheme  which  we  shall 
quote  is  one  founded  upon  modifications  of  the  generative  function.^ 
ilunter’s  first  class,  or  Vivipara,  corresponds  with  the  Zootoka  oi 
Aristotle,  and  the  Mammalia  of  Linnmus  ; these  animals  develop 
their  young  in  the  uterus,  he  says,  from  a mixture  of  male  and 
female  intluence,  and  bring  forth  a living  offspring. 

The  second  class,  or  Ovovivipara,  is  a subdivision  of  the  Ootoha 
or  Ovipara  of  Aristotle,  and  “hatch  their  young  from  an  egg  in 
the  oviduct,  as  vipers,  slow-w'orms,  some  lizards,  newts,  and  the 
dog-fish.” 

The  third  class  inc]ndes  the  Ooipara,  or  “ such  animals  as  exclude 
their  eggs,  which  are  afterwards  hatched  out  of  the  body  but 
this  character,  as  Hunter  justly  observes,  “ takes  in  a wide  field.” 

Fourthly,  he  says,  “ We  have  animals  which  propagate  by  slips, 
and  that  in  two  different  ways,  one  by  a piece  cut  off',  the  other  by 
branches  growing,  and  these  falling  off',  and  producing  a distinct 
animal.”  Hunter  here  rightly  regards  the  fissiparous  and  gemni- 
parous  modes  of  generation  as  modifications  of  the  same  reproduc- 
tive process  which  is  characteristic  of  that  lowest  group  of  animals 
previously  indicated  by  tlie  molecular  condition  of  the  nervous 
system,  and  “ where  every  other  principle  of  the  animal  is  diffused 
through  the  whole,”  a condition  which  in  the  animal  kingdom 
seems  essential  to  the  possession  of  the  property  of  fissiparous  re- 
production, or  to  a division  of  the  whole  body  with  a continuance 
of  the  vital  properties  in  the  parts.  Hunter  seems,  howmver,  to  have 
felt  how  unsatisfactorily  and  artificial  was  the  classification  founded 
on  modes  of  generation,  for  he  adds  in  the  manuscript  in  which  the 
above  sketch  is  given,  “ Animals  of  any  particular  class  have  not 
one  way  only  of  propagating  their  species,  excepting  the  more 
perfect,  or  first  class  according  to  hearts,  for  wm  have  the  second 
and  even  the  third  class  aping  the  first,  and  attempting  to  be  vivi- 
parous, as  vipers,  lizards,  and  some  fishes,  as  the  skate.”  He  might 
have  added  examples  of  ovoviviparous  animals,  from  the  molluscous, 
articulate  and  radiate  classes, — classes  which  in  every  other  re- 
spect are  most  dissimilar.  This  idea  of  an  arrangement  of  the 
animal  kingdom  from  modifications  of  the  generative  function  was 
afterwards  carried  out  by  Sir  Everard  Home, J and  applied  by  him 
to  the  definition  of  the  narrower  or  subordinate  groups.  But  as  of 
all  single  characters  the  generative  system  affords  the  most  arbitrary 
and  unnatural  distinctions,  and  corresponds  least  with  the  modifi- 

* See  Carlisle,  Ori  the  Structure  and  CEconoiny  of  Taeniae,  Linnaean  Transac- 
tions, vol.  ii.,  p.  253,  and  Treatise  on  the  Blood,  p.  IIG,  of  the  present  edition. 

t See  Introduction  to  the  Physiological  Catalogue,  vol.  Hi.,  p.  vi. 

fi  See  \\\s  Syslema  Regni  Anintalis  7uinc  prirnum  ex  ovi  modificatlonibus  pro- 
positum.  Lectures  on  Comparative  Anatomy,  vol.  iii.,  p.  535. 


PREFACE. 


29 


cations  of  the  rest  of  the  organization,  a classification  of  animals 
based  upon  it  is  least  adapted  to  afford  any  of  the  conveniences  of 
even  an  artificial  system. 

In  the  Systema  JVatureB  of  Linnmus  the  first  of  the  characters  by 
which  the  six  classes  of  animals  are  distinguished  is  derived  from 

O 

modifications  of  the  structure  of  the  heart,  as  follows: 

“ Mammalia,  Cor  biloculare,  biauritum  ; 

Aves,  Cor  biloculare,  biauritum  ; 

Amphyhia,  Cor  uniloculare,  uniauritum; 

Pisces,  Cor  uniloculare,  uniauritum; 

Insecta,  Cor  uniloculare,  inauritum  ; 

Vermes,  Cor  uniloculare,  inauritum.” 

But  Linnaeus  combines  the  cardiac  character  with  others  derived 
from  the  nature  of  the  blood,  the  condition  of  the  respiratory  organs, 
the  structure  of  the  mouth  and  generative  organs,  the  nature  of  the 
integuments,  &c.,  and  thus  makes  an  approach  to  a natural  system 
of  arrangement. 

Hunter,  in  his  distribution  of  animals  into  different  classes  ac 
cording  to  the  structure  of  the  heart,  uses  the  cardiac  character 
singly,  and  produces  a purely  artificial  arrangement ; but  his 
superior  anatomical  knovdedge  manifests  itself  in  the  accuracy 
with  which  he  defines  the  condition  of  the  circulating  organ 
characteristic  of  the  different  groups. 

His  first  class  includes  the  Mammalia  and  Aves  of  Linneeus,  and 
he  proposes  to  call  it  Tetracoilia,  the  heart  having  four  cavities, 
viz.,  two  ventricles  and  two  auricles. 

The  second  class.  Tricoilia,  includes  those  animals  which  have  a 
heart  with  three  cavities,  viz.,  one  ventricle  and  two  auricles,  and 
corresponds  with  the  Amphibia  of  Linnaeus.  The  anatomical  inac- 
curacy in  the  Linnasan  character,  although  so  early  corrected  by 
Hunter,  long  retained  its  ground  in  the  systematic  works  of  conti- 
nental naturalists,  and  continued  to  be  erroneously  applied  to  the 
Batrachian  section  of  the  Linnaean  Amphibia  until  a very  recen 
period.* 

'*  The  two  auricles  were  after  the  time  of  Linnaeus  successively  assigned  in 
systematic  works  to  the  Chelunia  and  Sauria.  Bluraenbach  long  continued  to 
assert  that  serpents,  at  least  those  of  Germany,  had  but  one  auricle  ; Cuvier  al- 
lowed them  two,  but  denied  this  higher  structure  of  the  heart  to  the  Batrachia 
“ Ils  n’ont  au  coeur  qu’une  seule  oreillette  et  un  seul  ventricule.”  Regne  Animal, 
ii.,  p.  101,  edit.  1829.  Meckel  also  ascribes  this  structure  to  the  generality  of 
the  Batrachia:  “Die  Batrachier  haben  die  einfachste  Herzform.  Das  Herz 
besteht  sehr  allgemein  nur  aus  einer  Vorkammer  und  einer  Kammer.”  Vergl. 
Anat.,  band  v.,  p.  215.  The  more  complicated  structure  of  the  heart  was,  how- 
ever, truly  described  in  the  anourous  Batrachia  by  Dr.  John  Davy  in  1825  ; his 
observations  were  confirmed  by  Prof.  Weber  in  18.32  ; and  in  April,  1834,  I 
communicated  to  the  Zoological  Society  the  result  of  a series  of  examinations 
of  the  hearts  of  the  Batrachia,  which  proved  that  the  whole  order,  including  the 
perennibranchiate  species,  had  distinct  auricles  for  the  pulmonic  and  systemic 
blood,  since  which  time  the  tripartite  structure  of  the  heart  has  been  universally 
assigned  to  the  Batrachia, 


4 


30 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  third  class,  or  Dicoilia,  includes  those  which  have  two 
cavities  in  the  heart,  or  one  ventricle  and  one  auricle,  and  consists 
of  the  gill-fish.  The  sharks  and  rays  were  included  by  Hunter  in 
this  class,  but  the  dicoelous  or  bipartite  structure  of  their  heart  pre- 
sented no  obstacle  to  their  junction  with  the  Amphibia  in  the 
Linnsean  arrangement. 

Umlefs fourth  class,  or  Monocoilia,  characterized  by  a heart 
with  but  one  cavity  or  ventricle,  without  an  auricle,  is  restricted  to 
insects  of  all  kinds,  /.  e.  to  the  articulate  animals  included  by  Hunter 
in  his  second  class  according  to  brains. 

By  Linnaeus  the  character  is  applied  to  all  invertebrate  animals 
without  exception.  Hunter,  with  more  truth,  defines  a fifth  class 
of  animals,  by  the  name  of  dicardia,  “ whose  stomach  and  heart 
are  the  same  bod}^  as  in  the  blubber  {Medusa)  and  polypus.”  But 
even  with  this  improvement,  the  Cardiac  arrangement  of  animals, 
as  proposed  by  Hunter,  is  very  incomplete.  The  whole  division  of 
the  molluscous  animals  is  left  out  of  the  system.  This  did  not, 
however,  arise  from  a want  of  the  knowledge  of  the  structure  of 
the  heart  in  those  animals.  Hunter  well  knew  the  complex  condi- 
tion of  the  circulating  organ  in  the  cuttle-fish,  a condition  which, 
had  he  rigorously  carried  out  his  scheme  of  classification  according 
to  hearts,  would  have  indicated  a class  above  the  mammalia,  and 
to  which  the  name  of  Heptacoilia  might  have  been  applied,  since 
there  are  three  distinct  ventricles,  one  systemic  and  two  pulmonic, 
and  four  auricles  or  venous  sinuses  in  this  and  other  dibranchiate 
cephalopods.  In  the  snail  and  other  gastropods  Hunter  had  recog- 
nised a structure  of  the  heart  as  complex  and  perfect  as  in  fish,  but 
having  a different  relation,  both  as  regards  function  and  position,  to 
the  respiratory  organ. ^ In  still  lower  Mollusca  Hunter  had  detected 
the  existence  of  two  distinct  auricles,  with  one  ventricle;!  but  his 
perception  of  the  physiological  relations  of  these  different  cavities 
prevented  him  from  associating  the  mussel  with  the  tortoise,  on 
account  of  this  tricoelous  structure  of  the  heart.  We  may  thus 
perceive  amidst  the  defects  of  this  system  of  arrangement  an  evident 
advance  towards  a more  natural  distribution  of  animals,  especially 
of  the  invertebrata,  than  that  which  w’as  generally  accepted  at  the 
period  when  Hunter  wrote.  We  associate  this  progress  with 
Hunter’s  superior  knowledge  of  the  organization  and  mconomy  of 
animals  as  its  just  and  natural  cause,  and  we  proceed  to  adduce 
additional  evidences  of  Hunter’s  attempts  to  frame  a natural 
arrangement  of  animals. 

Perceiving  that  the  modifications  of  the  heart  alone  w^ere  inade- 
quate to  the  formation  of  a natural  and  symmetrical  classification 
of  animals,  he  next  tested  the  efficiency  of  characters  taken  from 
conditions  of  the  respiratory  system,  and  proposed  the  following 
scheme : 

The  first  class  includes  all  those  animals  which  have  lungs  with 
cells  through  the  whole,  and  a diaphragm. 

♦ On  the  Blood,  vol.  iii.,  p.  172. 


t Ibid.,  p.  172. 


PREFACE. 


31 


“ The  second  class,  all  those  which  have  their  lungs  attached  to 
the  ribs,  so  as  to  confine  them  to  their  place. 

“ The  third  class,  all  those  whose  lungs  come  into  the  belly  and 
are  loose. 

“ The  fourth  class,  all  those  whose  lungs  are  in  their  necks,  called 

“ The  fifth  class,  all  those  whose  lungs  are  in  their  sides.”’* 

In  this  scheme  we  have  most  exact  and  concise  characters  of  the 
four  classes  of  vertebrate  animals,  as  afforded  by  the  breathing 
organs ; and  in  this  case  Hunter  was  enabled  by  his  profound 
anatomical  knowledge  to  rise  far  above  Linnseus. 

In  the  Systemce  Natures,  the  Mammalia  and  Aves,  which  corres- 
pond with  Hunter’s  first  and  second  classes,  according  to  the  organs 
of  respiration,  have  both  the  same  characters  assigned  to  them, 
“ pulmones  respirantes  reciproce,”  while  the  Amphibia,  to  which 
Hunter’s  third  class  corresponds,  are  said  by  Linnreus  to  have 
“pulmones  spirantes  arbitrarie.”  Neither  Hunter  nor  Linnaeus, 
however,  arrived  at  the  perception  of  that  condition  of  the  respira- 
tory organs  which  characterizes  their  first  four  classes  in  common, 
viz.,  that  the  breathing  organs  communicate  with  the  mouth ; nor 
am  I aware  that  the  Vertebrata  have  ever  been  distinguished  in 
any  system  as  oral  breathers,  in  contradistinction  to  the  Mollusca, 
which  may  be  termed  anal  breathers,  and  to  the  Articulata,  which 
respire  by  apertures  or  branchial  organs  arranged  symmetrically 
at  the  sides  of  the  body. 

We  have  thus  traced  Hunter  in  his  character  as  a systematic 
zoologist  through  a series  of  attempts  at  the  arrangement  of  the 
animal  kingdom,  in  which,  like  the  indefatigable  Adanson  in  a sister 
science,  considering  each  organ  by  itself,  he  formed,  by  pursuing 
its  various  modifications,  a series  of  groups  characterized  by  that 
organ  alone  ; and  doing  the  same  for  another  organ  and  another, 
thus  constructed  a collection  of  systems  of  arrangement,  each  arti- 
ficial, because  each  was  founded  upon  the  variations  of  a single  as- 
sumed organ. 

It  would,  however,  be  doing  injustice  to  Hunter  to  adduce  the 
evidences  of  these  attempts  only.  In  that  division  of  the  animal 
kingdom  where  he  had  pushed  his  researches  furthest,  he  aims  to 
establish  a more  natural  classification,  by  tracing  the  variations  of 
all  the  important  organs,  and  keeping  in  view  the  different  value  of 
each  character;  and  thus  he  enunciates  several  general  anatomical 
and  physiological  truths.  The  following  are  the  characters  which 
he  assigns  to  the  different  classes  of  the  animals  now  called  Verte- 
brate. 

“ The  properties  of  the  First  Class,  which  includes  both  sea  and 
land  animals,  are 

“ Heart,  made  up  of  four  cavities,  essential. 

Lungs,  divided  into  small  cells,  and  confined  to  a proper  cavity. 


Physiological  Catalogue,  Introduction  to  the  Third  Volume,  p.  v. 


32 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


the  enlargement  of  which  is  the  cause  of  respiration  ; essential, 
Respiration  quick  (and  I believe  this  is  the  only  class  in  which 
it  is  so) ; essential. 

“ Give  suck;  essential. 

“ Pai'ts  of  generation,  made  up  of  testes  and  one  penis  in  the 
male  ; the  testes  sometimes  within  and  sometimes  without  the 
abdomen,  but  pass  forwards.  Clitoris,  vagina,  uterus  or 
uteri.  Fallopian  tubes,  and  ovaria,  in  the  female:  all  es- 
sential: 

^’•Kidneys,  high  up  in  the  abdomen;  circumstantial. 

“ Organ  of  hearing,  an  external  canal  to  the  ear,  membrana 
tympani  concave  externally,*  a cochlea  ; circumstantial, 

“ The  animals  of  this  class  are  by  much  the  most  perfect,  whether 
sea  or  land.  There  is  a gradation  from  the  land  to  the  sea 
animals,  viz.,  otter,  seal,  hippopotamus,  w'hale. 

“ The  Second  Class  is  confined  to  the  Birds  entirely.  I do  not 
know  of  any  animal  of  this  class  but  what  has  all  the  characteristics 
of  the  bird.  They  vary  less  in  any  of  their  parts  than  the  first 
class.f 

Lungs,  attached  to  the  ribs,  that  they  may  move  with  them: 
lungs  perforated ; membranous  bags  in  the  abdomen  that  re- 
ceive air  in  respiration;  something  like  a diaphragm. 

“ Parts  of  generation,  ova  crustaceous  ; one  oviduct ; one  penis, 
and  that  grooved;  no  bladder.  Oviduct  in  the  female,  and 
penis  with  the  vasa  deferentia  in  the  male,  all  open  in  the 
same  cavity  with  the  anus. 

“ Liver,  divided  into  two  lobes  ; cyst-hepatic  ducts. 

“ Organ  of  hearing,  little  external  passage  to  the  ear ; membrana 
tympani  convex  externally,  but  one  bone  (ossiculum  auditus) ; 
no  cochlea. 

“Feathers;  wings;  two  legs;  long  neck ; bill;  membrana  nic- 
titans ; bursa  Fabricii. 

“ There  is  none  of  this  class  that  belong  entirely  to  sea  animals; 
but  this  class  may  be  said  to  possess  in  some  measure  three 
elements,  viz.,  air,  earth,  and  water;  but  they  live  no  more 
in  the  air  than  other  animals,  for  it  is  only  for  their  progres- 
sive motion. 

“ In  the  Third  Class  we  shall  find  some  parts  similar  to  the  second. 
The  third  class  may  be  divided  into  two,  for  they  are  not 
exactly  alike,  but  one  seems  to  partake  of  the  second  and 
third  ; as  it  w'ere,  made  up  of  both.  The  first  division  of  the 
third  class,  then,  is  the  Lizard  and  Serpent  kind.  They  have 

“ Heart,  two  auricles,  one  ventricle,  two  aortas  which  unite  in  the 
abdomen. 

* This  appears  to  have  been  written  before  Mr.  Hunter  had  dissected  the  organ 
of  hearing  in  the  whale.  See  p.  380,  and  note*. 

f So  also  Cuvier : “ De  toutes  les  classes  d’animaux,  celle  des  oiseaux  est  la 
mieux  characterises,  celle  dont  les  especes  se  ressemblent  le  plus.” — Regne 
Jinim.,  i.  p.  310. 


PREFACE. 


33 


“ Lungs,  loose  bags,  which  lie  in  the  thorax  and  abdomen,  only 
partially  divided.  No  diaphragm. 

“ Kidneys,  in  the  lower  part  of  the  abdomen.  No  bladder.^ 
Parts  of  Generation,  iwo  penises,  grooved, t which  are  in  the 
tail.  ISome  oviparous,  eggs  without  shells  ; others  viviparous, 
but  not  as  the  First  Class. 

“ Some  have  legs,  others  none ; some  a membrana  tympani, 
which  is  convex  outwardly,  as  the  lizard ; others  none,  as  the 
snake. 

“ The  other  part  of  this  class,  which  may  be  termed  the  Fourth, 
or  the  Amphibious,  are  more  closely  allied  to  Fish  than  what  the 
fish  of  the  first  class  are.J  These  are  the  common  amphibious 
animals,  viz.  frogs,  turtles,  efts,  &c.  This  is  also  very  similar  to 
the  two  former,  and  is  nearly,  as  it  were,  a mixture  of  both,  yet 
the  most  essential  parts  belong,  or  are  similar  to  the  last. 

Heart,  two  auricles,  as  in  the  Third  ; one  ventricle,  as  in  the 
Third;  aorta,  as  in  the  Third. 

“ Lungs,  as  in  the  Third. 

‘^Kidneys,  as  in  the  Third. 

“ Part  of  generations,  one  penis,  as  in  the  Second  Class  ; penis 
grooved,  as  in  the  Second  and  Third.  Some  oviparous,  as  the 
frog;  others  vivaparous  as  the  salamander. 

“ Organ  of  Hearing,  some  have  a membrana  tympani,  as  the 
frog  ; others  none,  as  the  tortoise.§ 

“ The  Fourth  or  Fifth  Class  (according  as  the  two  preceding 
are  regarded  as  subdivisions  of  one  class,  or  as  two  distinct  classes) 
consists  of  Fishes,  and  is  very  distinct  from  the  former  so  far  as  I 
know.” 

The  manuscript  from  which  the  preceding  remarkable  passages 
are  quoted,  and  which  is  printed  entire  in  my  Prefatory  Observa- 
tions to  the  Third  Volume  of  the  Physiological  Catalogue,  contains 
no  characters  of  the  Class  of  Fishes,  nor  any  relating  to  the  Inver- 
tebrate Classes.  It  is  in  the  definition  of  these  latter  classes,  and 
in  the  determination  of  the  wider  divisions  of  the  Invertebrata, 
which  were  equivalent  to  the  entire  vertebrate  group,  that  Cuvier 
chiefly  surpassed  Hunter  as  a systematic  zoologist.  Yet,  as  I have 
before  observed.  Hunter  rises  above  Linnaeus  even  in  this  depart- 
ment: he  had  seized  the  great  character  of  the  molluscous  sub- 
kingdom afforded  by  the  nervous  system,  and  had  well  defined  some 
of  the  subordinate  groups,  more  especially  that  which  Lamarck 
afterwards  termed  Tunicata,  and  which  Cuvier  denominates 

* This  character  is  not  applicable  to  the  lizards  ; but  the  crocodile  agree.s  with 
the  serpents  in  having  no  urinary  bladder. 

I The  crocodile  has  but  one. 

f {,  e.  Those  of  the  first  class  which  are  shaped  like  fish,  and  live  in  water, 
as  the  Cetacea. 

§ The  turtles  and  tortoises,  orChelonian  reptiles,  as  they  are  now  termed,  have 
a closer  affinity  to  the  lizards  than  to  the  Batrachia,  or  frogs  and  salamanders. 


34 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


“ Acephates  sans  CoqtdUesA  but  which  Hunter,  more  correctly, 
termed  “ soft-shelled,”  having  perceived  the  analogy  of  their  ex- 
ternal elastic  tunic  to  shell ; and  having  detected,  with  admirable 
skill,  the  relations  subsisting  between  the  Ascidias  and  Salpee  in 
different  individuals  dissected  by  him,  of  which  dissections  there 
remain  not  only  the  preparations,  but  several  beautiful  designs, 
with  the  original  descriptions.* 

Of  Hunter’s  appreciation  of  the  progression  of  affinities  we  have 
an  example  in  his  sketch  of  the  transition  from  the  terrestrial  to  the 
aquatic  Mammalia  ; and  I do  not  doubt  that  ere  long  zoologists 
will  uniformly  agree  in  the  propriety  of  passing  from  the  hippopo- 
tamus and  its  pachydermatous  congeners  to  thedugong  and  the  true 
Cetacea,  instead  of  interposing  the  Ruminantia  between  the  Pachy- 
dermata  and  Cetacea,  as  in  the  Cuvierian  system. 

Of  his  mode  of  considering  the  affinities  of  two  great  and  equal 
groups.  Hunter  has  left  the  following  specimen,  which  he  quaintly 
designates  “ Of  the  similarity  of  the  Fowl  with  the  three-cavity- 
hearted  gentry,  called  Amphibia .” 

“ The  lungs  of  the  fowl  open  into  their  air-cells  or  bags  that 
are  in  the  cavity  of  the  belly.  The  lungs  in  the  Amphibia  are  con- 
tinued into  the  belly,  are  cellular  at  the  upper  part,  but  in  most,  as 
the  snake,  become  smooth  bags  at  the  lower  end,  as  it  were, 
answering  the  same  purpose  as  the  abdominal  bags  in  the  fowl. 
The  cells  of  the  lung-part  are  large. 

“No  proper  Diaj)liragm  in  either;  but  fowls  have  something 
similar  to  one.f 

“ The  Gall  is  green  in  both. 

“ The  Kidneys  are  placed  in  what  may  be  called  the  pelvis  ; in 
both  are  conglomerated  in  a particular  manner;  have  the 
ureter  ramifying  through  their  whole  substance,  and  entering 
into  the  rectum.  The  urine  is  a chalky  substance  in  many  of 
both,  and  a kind  of  slime  in  others. 

“ The  Testes  are  situated  in  the  abdomen  in  the  male  of  both. 

“ The  Vasa  deferentia  enter  the  rectum  in  both. 

“ The  Penis  is  grooved  in  both. 

“ Both  oviparous. 

“ Structure  oi  Ear  similar  in  both. 

“ Heart  very  different.  ” 

These  writings  fully  attest  the  enlarged  views  which  Hunter  en- 
tertained of  comparative  anatomy,  and  of  its  application  not  only 
to  the  establishment  of  sound  theories  of  the  functions  and  relative 
influences  of  the  diffeernt  organic  systems  in  the  animal  body,  but 
also  of  a natural  distribution  of  different  animals  into  classes  ar- 
ranged according  to  their  affinities.  It  is  in  this  respect  that  he 
has  more  especially  surpassed  those  of  his  countrymen  who  have 
immediately  succeeded  him  in  the  same  field  of  inquiry,  and  w'hose 


See  Plates  5,  G,  and  7,  vol.  i.  Physiological  Catalogue. 


\ See  p.  196. 


PREFACE. 


35 


labours  in  comparative  anatomy  have  not  been  productive  of  ade- 
quate results,  chiefly  from  being  restricted  to  the  narrower  channel 
of  their  physiological  application. 

The  museum  of  Hunter  is  the  chief,  but  not  the  sole  depository 
of  the  dissections  by  which  he  established  the  general  principles  to 
which  we  have  alluded. 

Hunter  had  passed  his  thirtieth  year  before  he  had  collected  a 
single  preparation  for  himself.  All  that  he  had  made  before  that 
time  were  added  to  his  brother’s  collection,  which  is  now  the  orna- 
ment of  the  University  of  Glasgow.  In  commencing  his  indepen- 
dent labours,  in  anatomy,  he  conceived  the  idea  of  a collection, 
in  which  the  illustrations  of  the  human  organization  should  form  a 
part  only  of  a general  display  of  all  the  types  and  modifications  of 
animal  structure,  and  practically  he  was  the  first  who  reduced  the 
scattered  facts  of  comparative  anatomy  to  a connected  system. 

When  Hunter  had  brought  his  museum  to  an  approximate  degree 
of  perfection,*  he  then  set  apart  certain  days,  in  which  he  exhibited 
and  explained  to  some  chosen  minds  which  could  respond  to  the 
conceptions  of  his  own,  his  great  scheme,  embracing  the  demon- 
stration of  all  the  leading  modifications  of  every  organ  of  the  ani- 
mal body,  and  of  the  different  stages  which  each  organ  undergoes 
in  its  development,  to  fulfil  the  functions  it  is  requirecl  to  perform  in 
the  highest  organisms. 

Amongst  the  enlightened  men  who  enjoyed  the  inestimable  advan- 
tage of  listening  to  the  explanations  which  the  founder  of  the  collec- 
tion gave  of  his  own  labours,  and  of  their  scope  and  tendency,  were 
Camper,  Poli,  Scarpa,  and  the  now'  venerable  Blumenbach. 

Camper,  as  a contemporary,  and  in  some  respects  a rival  of 
Hunter,  may  have  been  less  infiuenced  in  the  general  tenor  and 
success  of  his  investigations  in  comparative  anatonoy,  by  this  cir- 
cumstance, than  the  last  named  and  younger  naturalists  and  physiolo- 
gists. 

We  cannot  but  suppose  that  the  spectacle  of  the  organization  of 
so  many  rare  marine  animals,  beautifully  displayed  by  so  consummate 
a practical  anatomist  as  Hunter,  must  have  had  a lasting  influence  on 
the  mind  of  Poli;  and  it  is  not,  perhaps,  assuming  too  much  to  trace  to 
this  source  the  taste  for  anatomy'  and  the  stimulus  to  the  indefatiga- 
ble and  minute  dissections,  of  the  Mediterranean  mollusca,  and  the 
magnificent  illustrations  of  their  organization,  which  have  justly  im- 
mortalized their  author. 

In  contemplating  the  gradational  and  connected  series  of  the 
organs  of  animals,  which  Blumenbach  must  have  witnessed  for  the 
first  time  in  the  museum  of  Hunter,  that  learned  and  accomplished 
physiologist  was  doubtless  led  vividly  to  appreciate  the  cumulative 
force  with  which  comparative  anatomy  urges  the  onward  progress 
of  physiological  science  w'hen  all  its  scattered  facts  are  concen- 

* In  the  year  1787.  See  Home’s  Lectures  on  Comparative  Anatomy,  vol.  i. 
p.  7.  and  vol.  i.  p.  78  of  the  present  edition  of  Hunter’s  Works. 


36 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


trated  into  one  orderly  system.  In  his  subsequent  publications  of 
the  first  systematic  treatise  of  comparative  anatomy  the  erudition 
of  Blumenbach  supplied  many  of  those  links  in  the  series  of  animal 
structures  which  Hunter  derived  from  Nature’s  orieinal  sources. 

O 

In  estimating,  therefore,  the  share  which  Hunter  had  in  advancing 
comparative  anatomy  and  physiology,  his  annual  demonstrations  of 
his  collection  to  such  individuals  as  we  have  instanced  must  not  be 
overlooked.  We  may  admit  that  while  so  vast  a proportion  of  the 
stores  of  his  experience  lay  buried  in  unpublished  manuscripts,  his 
strue  station  in  the  temple  of  Science  could  hardly  be  discerned ; 
but,  independently  of  these  manuscripts,  we  cannot  hesitate  in  allow- 
ing that  his  published  works,  full  of  profound  and  original  views,  com- 
bined with  the  spectacle  of  his  wonderful  dissections,  must  have 
effected  more  than  had  been  done  by  any  previous  author  towards 
raising  the  science  of  comparative  anatomy  in  the  scale  of  human 
knowledge. 

Now,  however,  we  have  to  estimate  the  scientific  character  of 
Hunter  from  more  extended  grounds. 

Enjoying  the  same  privilege  of  consulting  his  museum,  which  the 
contemporaries  of  Hunter  so  highly  esteemed,  we  also  possess  the 
advantage  of  studying  it  with  the  aid  of  those  explanations  of  its 
scope  and  nature  which  its  great  founder  had  left  with  a view  to 
ulterior  publication. 

Thanks,  to  the  devotion  of  the  last  of  Hunter’s  pupils  to  the 
memory  of  his  great  master,  the  evidences  of  Hunter’s  discoveries 
and  labours,  as  recorded  in  his  collections,  are  in  a better  state  of 
preservation  at  this  moment  than  they  were  nearly  fifty  years  ago, 
when  they  first  fell  to  the  care  and  charge  of  Mr.  Clift.  And  here 
I embrace  with  pleasure  the  opportunity  of  expressing  my  grateful 
thanks  to  that  gentleman  for  the  kind  aid  which  I have  on  every 
needful  occasion  received  from  him  during  the  impression  of  the 
present  work,  and  of  recording  my  deep  sense  of  the  advantages 
which  I have  derived  from  a long  intercourse  with  one  whom  I 
ever  shall  regard  as  the  best  of  friends  and  worthiest  of  men. 

It  is  to  the  zeal  and  industry  which  induced  Mr.  Clift  to  tran- 
scribe portions  of  the  Hunterian  manuscripts,  at  a period  when  he 
little  suspected  their  ultimate  fate,  that  we  owe  our  additional 
knowledge  of  the  philosophical  views  which  Hunter  entertained  of 
the  application  of  anatomical  facts,  and  of  the  general  principles 
which  he  had  deduced  from  them.  As  such  of  these  extracts  from 
the  Hunterian  Manuscripts  as  have  been  quoted  in  the  present  work 
have  already  been  printed  in  the  Catalogues  of  the  Hunterian  Col- 
lections published  under  the  auspices  of  the  Council  of  the  Royal 
College  of  Surgeons,  it  is  competent  for  any  one  to  judge  of  the 
grounds  on  which  I have  endeavoured  to  show  that  Hunter,  as  a 
comparative  anatomist,  merits  a higher,  and  altogether  different 
station  in  science  than  has  been  awarded  to  him  by  Cuvier. 

Instead  of  viewing  Hunter  as  one  who  had  merely  contributed  a 
secondary  proportion  of  detached  facts  to  the  general  but  unarranged 


PREFACE. 


37 


stock  of  materials  in  comparative  anatomy,  it  appears  to  me  that 
he  marks  a new  epoch  in  its  history,  and  that  the  historian  of  the 
natural  sciences  has  just  and  sufficient  grounds  for  regarding  Hunter 
as  the  first  of  the  moderns  who  treated  of  the  organs  of  the  animal 
body  under  their  most  general  relations,  and  who  pointed  out  the 
anatomical  conditions  which  were  characteristic  of  great  groups  or 
classes  of  animals  : as  one,  in  short,  throughout  whose  works  we 
meet  with  general  propositions  in  comparative  anatomy,  the  like  of 
which  exist  not  in  the  writings  of  any  of  his  contemporaries  or  pre- 
decessors, save  in  those  of  Aristotle. 

RICHARD  OWEN. 

November  \5th,  1837. 

N.B.  The  Editor’s  Notes  are  distinguished  from  the  Author’s  by  being 
placed  within  brackets. 


•®M  i C . 

T 

■■ 

! - 


-5.  '-r. 


< 


!>»• 

- fcf* 


t 


'i* ‘f  ■'• 


•"  -y  ' ■ : ’’'  'liw  . 


CONTENTS. 


Page 


Preface  of  the  Editor  ........ 

1.  Description  of  the  Situation  of  the  Testis  in  the  foetus,  with  its 

descent  into  the  Scrotum  ...... 

2.  Observations  on  the  Glands  situated  between  the  Rectum  and 

Bladder,  called  Vesiculae  Seminales  .... 

3.  Account  of  the  Free-martin  ...... 

4.  Account  of  an  extraordinary  Pheasant  .... 

5.  Experiments  to  determine  the  effect  of  extirpating  one  ovarium 

upon  the  number  of  Young  produced  . . . . 

6.  Case  of  a young  Woman  who  poisoned  herself  in  the  first  month 

of  Pregnancy,  with  a description  of  the  Uterus 

7.  On  the  Structure  of  the  Placenta  ..... 

8.  Observations  on  the  Placenta  of  the  Monkey 

9.  Account  of  a Woman  who  had  the  Small-pox  during  Pregnancy, 

and  who  seemed  to  have  communicated  the  same  Disease  to  the 
Foetus  ......... 

10.  Some  Observations  on  Digestion  \ 

11.  On  the  Digestion  of  the  Stomach  after  Death 


7 

41 

58 

70 

79 

85 

89 

93 

103 


105 

112 

144 


12.  On  a Secretion  in  the  Crop  of  breeding  Pigeons,  for  the  nourish- 


ment of  tlieir  Young  ......  149 

13.  Observations  on  the  Gillaroo  Trout,  commonly  called  in  Ireland 

the  Gizzard  Trout  . . . . . . , 151 

14.  Experiments  and  Observations  on^nimals  with  respect  to  the 

power  of  producing  Heat  ...  ...  155 

15.  Experiments  and  Observations  on  Vegetables  with  respect  to  the 

power  of  producing  Heat  ......  177 

16.  Proposals  for  the  Recovery  of  Persons  apparently  drowned  185 

17.  Account  of  certain  Receptacles  of  Air  in  Birds,  which  communi- 

cate with  the  Lungs  and  Eustachian  Tube  . . . 194 

18.  Description  of  the  Nerves  which  supply  the  Organ  of  Smelling  204 

19.  Description  of  some  Branches  of  the  Fifth  Pair  of  Nerves  209 

20.  Croonian  Lecture  on  Muscular  Motion,  No.  I.  . . 211 

21  Do.  Do.  Do.  Do.  No,  II.  . . 238 

22.  Do.  Do.  Do.  Do.  No.  HI.  . . 254 

23.  Do.  Do.  Do,  Do.  No.  IV.  . . 262 

24.  Do.  Do.  Do,  Do.  No.  V.  . . 265 

25.  Do.  Do.  Do.  Do.  No.  VI.  . . 277 


40 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Page. 

26.  On  the  Use  of  the  Oblique  Muscles  ....  282 

27.  On  the  Colour  of  the  Pigmentum  of  the  Eye  in  different 

Animals  .........  285 


28.  On  the  Crystalline  Lens,  or  some  Facts  relative  to  the  late  Mr. 


John  Hunter’s  Preparation  for  the  Croonian  Lecture  . 292 

29.  Account  of  the  Organ  of  Hearing  in  Fishes  . . ^ 297 

30.  Experiments  on  Absorption  by  Veins  ....  303 

31.  Experiments  and  Observations  on  the  Growth  of  Bones  . 319 

32.  Observations  tending  to  show'  that  the  Wolf,  Jackal  and  Dog  are 

all  of  the  same  species  ......  323 

33.  Observations  on  the  Structure  and  (Economy  of  Whales  . 334 

34.  Notes  on  the  Anatomy  of  the  Jerboa  ....  391 

35.  Anatomical  Description  of  the  Amphibious  Bipes  of  Ellis  (Siren 

lacertani,  Linn.)  .......  392 

36.  On  the  Electric  Property  of  the  Torpedo  . . . 396 

37.  Anatomical  Observations  on  the  Torpedo  . . . 404 

38.  Account  of  the  Gymnotus  eleciricus  ....  408 

39.  Observations  on  Bees  . . . . . . 415 

40.  Anatomical  Remarks  on  a New  Marine  Animal  (Serpula  gigan- 

iea,  Pallas)  ........  456 

41.  Observations  on  the  Fossil  Bones  presented  to  the  Royal  Society 

by  His  Most  Serene  Highness  the  Margrave  of  Anspach  459 

42.  Descriptions  of  some  Animals  from  New  South  Wales  . 468 

Of  the  Kangaroo  (macropus  major,  Shaw)  . . 472 

Of  the  Potoroo  (Hypsiprymnus  murinus,  Illiger)  . 474 

Of  the  Hopoona  Roo  (Pelaurus  Taguanoid.es,  I)esmarest  475 
Of  the  Wha  Tapoua  Roo  (Phalangista  Vulpinu,  Geoffroy)  476 
Of  the  Tapao  Tafa  (P/iascog-flZe^enjcj7/aA<,  Temminck)  . 477 

Oi  \\\Q  Dingo  (Canis  Australasiss)  . . . 479 


A 


TREATISE 


ON  THE 

ANIMAL  (ECONOMY. 


1.  A DESCRIPTION  OF  THE  SITUATION  OF  THE  TES- 
TIS IN  THE  FCETUS,  WITH  ITS  DESCENT  INTO 
THE  SCROTUM. 

A DISCOVERY  in  any  art  not  only  enriches  that  with  which  it  is  im- 
mediately connected,  but  elucidates  all  those  to  which  it  has  any  re- 
lation. The  knowledge  of  the  construction  of  a human  body  is 
essential  to  medicine,  therefore  every  improvement  in  anatomy 
must  throw  additional  light  on  that  branch  of  science.  These  im- 
provements strike  more  forcibly  if  they  are  on  subjects  quite  new 
or  little  understood  ; and  this  effect  is  well  illustrated  by  the  ad- 
vantages which  pathology  has  derived  from  the  discovery  of  the 
lymphatics  being  the  absorbent  system ; and  likewise  by  that  case 
of  hernia,  where  the  intestine  lies  in  contact  wdth  the  testicle  ; which 
has  been  perfectly  explained  by  the  discovery  of  the  original  seat 
of  the  testicle  being  in  tbe  abdomen. 

Several  years  before  Haller’s  Opuscula  Pathologica  were  pub- 
lished, my  brother  informed  me,  that  in  examining  the  contents  of 
the  abdomen  of  a child,  stillborn,  about  the  seventh  or  eighth  month, 
he  found  both  the  testicles  lying  in  that  cavity,  and  mentioned  the 
observation  with  some  degree  of  surprise.  By  this  we  are  enabled 
to  account  for  a circumstance  that  sometimes  happens  in  the  scrotal 
hernia,  as  depending  on  the  discovery  that  the  testis  is  formed  in 
the  abdomen,  and  which  we  could  never  explain  to  our  satisfaction 
till  the  publication  of  the  Opuscula,  to  which  Dr.  Hunter  alludes, 
(Commentaries,  page  72,)  in  the  following  words: 

“ In  the  latter  end  of  the  year  1755,  when  I first  had  the  pleasure 

5 


42 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


of  reading  Baron  Haller’s  observations  On  the  Hernia  Congenita,* 
it  struck  my  imaginationf  that  the  state  of  the  testis  in  the  foetus, 
and  its  descent  from  the  abdomen  into  the  scrotum,  would  explain 
several  things  concerning  ruptures  and  the  hydrocele,  particularly 
that  observation  which  Mr.  Sharp  had  communicated  to  me,  viz., 
that  in  ruptures  the  intestine  is  sometimes  in  contact,  with  the  testis. 
I communicated  my  ideas  upon  this  subject  to  my  brother,  and 
desired  that  he  would  take  every  opportunity  of  learning  exactly 
the  state  of  the  testis  before  and  after  birth,  and  the  state  of  ruptures 
in  children.  We  were  both  convinced  that  the  examina  tion  of  those 
facts  would  answer  our  expectation,  and  both  recollected  having- 
seen  appearances  in  children  tliat  agreed  with  our  supposition,  but 
saw  now  that  we  had  neglected  making  the  proper  use  of  them. 

“ In  the  course  of  the  winter  my  brother  had  several  opportunities 
of  dissecting  fetuses  of  diflerent  ages,  and  of  making  some  draw- 
ings of  the  parts  ; and  all  his  observations  agreed  with  the  ideas  I 
had  formed  of  the  nature  of  ruptures,  and  of  the  origin  of  the  tunica 
vaginalis  propria  in  the  fetus.  But  till  those  observations  were 
repeated  to  his  satisfaction,  and  were  sufficiently  ascertained,  he 
desired  me  not  to  mention  the  opinion  in  my  lecture  ; and  therefore, 
when  treating  of  the  coats  of  the  testis,  and  of  the  situation  of  the 
hernial  sac,  &c.,  I only  put  in  this  temporary  caution,  that  I was 
then  speaking  of  those  things  as  they  are  commonly  in  adult  bodies, 
and  not  as  they  are  in  the  fetus:  and  at  last,  when  I was  conclud- 
ing my  lectures  for  that  season,  in  the  end  of  April  1756,  with  a 
course  of  the  chirurgical  operations,  I gave  a very  general  account 
of  my  brother’s  observations,  and  showed  both  the  drawing  of  fig.  2, 
which  was  then  finished,  and  the  subject  from  which  it  was  made.” 

The  following  observations  on  this  subject  were  taken  from  my 
notes,  and  published  by  Dr.  Hunter  in  his  commentaries  to  which 
I have  added  some  practical  remarks. 

“ Until  the  approach  of  birth,  the  testes  of  the  fetus  are  lodged 
within  the  cavity  of  the  abdomen,  and  may  therefore  be  reckoned 
among  the  abdominal  viscera.  They  are  situated  immediately 
below  the  kidneys,  on  the  fore  part  of  the  psore  muscles,  and  by  the 
side  of  tiie  rectum,  where  this  intestine  is  passing  down  into  the 

* Alberli  Ilalleri  OpuscuL  Paihohg.,  Laiisan.  1755,  8vo.,  page  53,  &c. 

f [Although  Haller  was  in  doubt  as  to  the  exact  period  of  the  descent  of  the 
testis,  and  in  error  as  to  the  cause  of  that  phenomenon,  yet  he  accurately  describes, 
in  the  original  paper  here  alluded  to,  the  original  relations  of  the  gland  to  the 
peritoneum  and  abdominal  viscera,  and  the  formation  of  the  tunica  vaginalis,  and 
thus  applies  the  facts  which  he  had  discovered  to  the  explanation  of  the  disease 
lie  was  considering.  “ Herniarum,  ni  fallor,  congenitarum  modus  hinc  elucescit, 
quo  generantur.  Patulus  est  processus  peritonasi  sub  renibus  positus,  qui  ex- 
pectat  testem  invitatque  aperto  ostio,  atque  eo  deorsum  ex  solita  lege  pulso 
urgetur,  inque  scrotum  una  descendit.  Cum  aiitem  his  in  corporibus  testes  eodem 
cum  intestinis  sacco  omnino  contineantur,  nihil  est  singularis  sive  inexpectati,  si 
ea  in  apertum  saccama  levi  vi  depressa  fuerint.”  [Upasc.  Fa/holng.,j>.  56.)  In 
this  paper  there  are  references  to  the  older  authors  who  had  noticed  the  abdominal 
position  of  the  testes  in  the  foetus.] 


SITUATION  OF  THE  TESTIS  IN  THE  FOETUS. 


43 


cavity  of  the  pelvis ; for  in  the  fcetus,  the  rectum,  which  is  much 
larger  in  proportion  to  the  capacity  of  the  pelvis  than  in  the  full- 
grown  subject,  lies  before  the  vertebrm  lumborum  as  well  as  before 
the  os  sacrum.  Indeed  the  case  is  pretty  much  the  same  with  re- 
gard to  all  the  contents  of  the  pelvis  ; that  is,  their  situation  is  much 
higher  in  the  foetus  than  in  the  adult.  The  sigmoid  flexure  of  the 
colon,  part  of  the  rectum,  the  greatest  part  of  the  bladder,  the 
fundus  uteri,  the  Fallopian  lubes,  &c.,  being  placed  in  the  foetus 
above  the  hollow  of  the  pelvis  in  the  common  or  great  abdominal 
cavity. 

“ While  the  testis  remains  in  the  abdomen  its  shape  or  figure 
is  much  the  same  as  in  the  adult,  and  its  position  or  attitude  the 
same  as  when  it  is  in  the  scrotum;  that  is,  one  end  is  placed  up- 
wards, the  other  downwards  ; one  flat  side  is  to  the  right,  the  other 
to  the  left ; and  one  edge  is  turned  backwards,  the  other  forwards; 
and  the  vessels  enter  the  posterior  edge  alike  in  both  the  fcetus  and 
adult.  As  the  testis  is  not  so  immediately  inclosed  in  the  surround- 
ing parts  while  it  is  in  the  loins,  its  position  may  be  a little  variable, 
and  the  most  natural  seems  to  be  when  the  anterior  edge  is  turned 
directly  forwards;  but  as  the  least  touch  of  anything  will  throw' 
that  edge  either  to  the  right  side  or  to  the  left,  then  the  flat  side  of 
the  testis  will  be  turned  forwards.  It  is  attached  to  the  psoas 
muscle  all  along  its  posterior  edge,  except  just  at  its  upper  ex- 
tremity; and  this  attachment  is  formed  by  the  peritoneum,  which 
covers  the  testis  and  gives  it  a smooth  surface,  in  the  same  manner 
as  it  envelopes  the  other  loose  abdominal  viscera. 

“ The  epididymis  lies  along  the  outside  of  the  posterior  edge  of 
the  testis,  as  when  in  the  scrotum,  but  is  larger  in  proportion,  and 
adheres  backwards  to  the  psoas.  When  the  fcetus  is  very  young, 
the  adhesion  of  the  testis  and  epididymis  to  the  psoas  is  vmry  narrow', 
and  then  the  testis  is  more  loose,  and  more  projecting  ; but  as  the 
foetus  advances  in  months,  the  adhesion  of  the  testis  to  the  psoas 
becomes  broader  and  tighter. 

“ The  vessels  of  the  testis,  like  those  of  most  parts  of  the  bodv, 
commonly  rise  from  the  nearest  larger  trunks,  viz.,  from  the  aorta 
and  cava,  or  from  the  emulgents. 

“The  artery  generally  rises  from  the  fore  part  of  the  aorta,  a 
little  below  the  emulgent  artery,  and  often  from  the  emulgent  itself, 
especially  in  the  right  side  of  the  body,  which  may  happen  the 
rather,  because  the  trunk  of  the  aorta  is  more  distant  from  the  right 
testis  than  from  the  left.  Sometimes,  but  much  more  rarely,  the 
spermatic  artery  springs  from  the  phrenic,  or  from  that  of  the 
capsula  renalis.  Besides  the  artery  which  rises  from  the  aorta,  or 
emulgent,  &c.,  the  testis  receives  one  from  the  hypogastric  artery, 
which  is  sometimes  as  large  as  the  other.  It  runs  upwards  from 
its  origin,  passing  close  to  the  vas  deferens  in  its  w'ay  to  the  testis. 
The  superior  spermatic  artery  sometimes  passes  before  the  lower 
end  of  the  kidney ; and  both  these  arteries  run  in  a serpentine 
direction,  making  pretty  large  but  gentle  turnings.  They  are  situ- 


44 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


ated  behind  the  peritoneum,  and  both  run  into  the  posterior  edge 
of  the  testis,  between  the  two  reflected  laminee  of  that  membrane, 
much  in  the  same  manner  as  the  vessels  pass  to  the  intestines 
between  tlie  two  reflected  laminae  of  the  mesocolon  or  mesentery. 

“ The  veins  of  the  testis  are  analogous  to  its  arteries,  but  com- 
monly change  sides  with  the  arteries  respecting  their  origins  from 
the  emulgents.  The  superior  spermatic  vein,  to  begin  with  its 
trunk,  rises  commonly  in  the  following  manner:  on  the  right  side, 
from  the  trunk  of  the  vena  cava,  a little  below  the  emulgent;  and 
on  the  left  side,  from  the  left  emulgent  vein.  The  reason  of  this 
difference  between  the  right  and  left  spermatic  vein,  no  doubt,  is 
because  the  cava  is  not  placed  in  the  middle  of  the  body;  so  that 
by  the  rule  of  ramification  which  is  observed  in  most  parts  of  the 
body,  the  cava  is  the  nearest  large  vein  of  the  right  side,  and  the 
emulgent  is  the  nearest  large  vein  of  the  left  side.  But  the  diffei’- 
ence  is  inconsiderable;  and  accordingly  we  sometimes  find  the 
right  spermatic  vein  coming  from  the  right  emulgent  vein ; and 
several  other  varieties  are  produced,  which  so  far  as  I can  observe, 
follow  no  precise  rule.  There  is  likew’ise  a spermatic  vein,  which 
rises  from  the  internal  iliac,  and  runs  up  to  the  testis  with  the  in- 
ferior spermatic  artery.  Both  the  spermatic  veins  run  behind  the 
peritoneum  with  their  corresponding  arteries,  and  go  into  the  poste- 
rior edge  of  the  testis,  w'here  they  are  lost  in  small  branches. 

“ The  nerves  of  the  testis,  like  its  blood-vessels,  come  fi’om  the 
nearest  source ; that  is,  from  tlie  abdominal  plexuses  of  the  inter- 
costal, especially  the  inferior  mesenteric  plexus.  They  run  to  the 
testis,  accompanying  its  blood-vessels,  and  are  dispersed  with  them 
through  its  substance.  The  testis,  therefore,  with  respect  to  its 
nerves,  may  be  reckoned  an  abdominal  viscus  ; and  this  observa- 
tion will  hold  good  when  applied  to  the  full-grown  subject ; as  well 
as  to  the  foetus  ; for  those  branches  of  the  lumbar  nerves  which  are 
commonly  said  to  be  sent  to  the  testis,  passing  through  the  tendon 
of  the  external  oblique  muscle,  in  reality  go  not  to  the  testis  itself, 
hut  to  its  exterior  coverings,  and  to  the  scrotum.”  p.  75. 

The  testicle  receiving  its  nerves  from  the  plexuses  of  the  inter- 
costal, accounts  for  the  stomach  and  intestines  sympathizing  so 
readily  with  it  and  its  particular  sensation,  and  for  the  eflhcts  arising 
in  the  constitution  upon  its  being  injured. 

“ The  epididymis  begins  at  the  outer  and  posterior  part  of  the 
upper  end  of  the  testis,  immediately  above  the  entrance  of  the  blood- 
vessels, where  it  is  thick,  round,  and  united  to  the  testis.  As  it 
passes  down  it  becomes  a little  smaller  and  more  flat,  and  is  only 
attached  backwards  to  the  testis,  or  rather  indeed  to  its  vessels;  for 
its  anterior  edge  lies  loose  against  the  side  of  the  testis  forwards ; 
and  at  its  lower  end  it  is  again  more  firmly  attached  to  the  body  of  the 
testis,  so  that  in  the  foetus  there  is  a cavity  or  pouch  formed  between 
the  middle  part  of  the  testis  and  the  middle  part  of  the  epididymis, 
more  considerable  than  is  commonly  observed  in  full-growm  sub- 
jects. As  the  body  grows,  the  epididymis  adheres  more  closely  to 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS, 


45 


the  side  of  the  testis;  and  its  greatest  part  is  made  up  of  one  con- 
voluted canal,  which  becomes  larger  in  size  and  less  convoluted 
towards  the  lower  end,  and  at  last  is  manifestly  a single  tube  run- 
ning a little  serpentine.  That  change  happens  at  the  lower  end  of 
the  testis,  and  there  the  canal  takes  the  name  of  vas  deferens. 

“ The  vas  deferens  is  a little  convoluted  or  serpentine  in  its  whole 
course,  but  is  less  so  as  it  comes  nearer  to  the  bladder;  instead  of 
running  upwards  from  the  lower  end  of  the  testis,  as  it  does  when 
the  testicle  is  in  the  scrotum,  while  that  remains  in  the  abdomen,  it 
runs  downwards  and  inwards  in  its  whole  course,  so  that  it  goes  on 
almost  in  the  direction  of  the  epididymis,  of  which  it  is  a continua- 
tion. It  turns  inwards  from  the  lower  end  of  the  epididymis,  under  the 
lower  end  of  the  testis,  and  behind  the  upper  end  of  a ligament  or 
gubernaculum  testis  (which  I shall  presently  describe) ; then  it  passes 
over  the  iliac  vessels,  and  over  the  inside  of  the  psoas  muscle, 
somewhat  higher  than  in  adult  bodies,  and  at  last  goes  between  the 
ureter  and  bladder  towards  the  basis  of  the  prostate  gland.”  p.  77. 

In  those  animals  where  the  testicles  change  their  situation  the  cre- 
master muscle,  wdiich  should  be  named  musculus  testis,  has  two 
very  different  positions  in  the  foetus  and  in  the  adult,  the  first  being 
the  same  as  in  those  animals  whose  testicles  remain  through  life  in 
the  cavity  of  the  abdomen  ; we  must  therefore  conclude  that  the 
same  purposes  are  answered  by  this  muscle  in  the  foetus  as  in  those 
animals. 

The  use  of  this  muscle,  when  the  testicle  is  in  the  scrotum,  ap- 
pears to  be  evidently  that  of  a suspensory ; for  I find  this  muscle  is 
strong  in  proportion  to  the  size  of  the  testicle  and  pendulous  situation 
in  other  animals.  But  what  purpose  it  answers  in  the  foetus,  or  in 
animals  whose  testicles  remain  in  the  abdomen,  is  not  easily  ima- 
gined, there  being  no  apparent  reason  why  such  a muscle  should 
exist.* 

The  cremaster,  or  musculus  testis,  appears  to  be  composed  of  the 
lower  fibres  of  the  obliquus  internus  and  transversalis  muscles  in  the 
foetus,  turning  upwards,  and  spreading  upon  the  anterior  surface  of 
the  gubernaculum,  immediately  under  the  peritoneum;  it  appears  to 
be  lost  on  the  peritoneum,  a little  way  from  the  testicle.  This, 
although  now  inverted,  is  more  evidently  seen  in  adult  subjects 
who  have  had  a hydrocele  or  rupture;  in  such  cases  the  muscle 
becomes  stronger  than  usual,  and  its  fibres  can  be  traced  spreading 
on  the  tunica  vaginalis,  and  seem  at  last  to  be  lost  upon  it,  near  to 
the  lower  end  of  the  body  of  the  testicle. 

The  nerves  which  supply  this  muscle  are  probably  branches  from 

* [The  cremaster  d oes  notin  fact  exist  in  the  true  iesticonda,  as  the  elephant,  hyrax, 
seal,  walrus,  the  Cetaceous  and  Monotrematous  Mammalia;  in  these  the  testes 
are  merely  supported  by  their  vessels  and  a fold  of  peritoneum  analogous  to  the 
broad  ligaments  of  the  uterus  and  ovaries  ; but  when  the  cremaster  is  met  with 
in  apparent  iesticonda  it  is  always  in  relation  to  a partial  or  temporary  escape  of 
the  testis  from  the  abdomen,  as  in  bats  and  most  insectivorous  Ferse,  and  in  many 
of  the  Glires,  as  the  rats,  squirrels,  beaver,  porcupine,  &c.] 


46 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  nerves  of  llie  obliquus  internus  and  transversalis  muscles  ;*  for 
the  same  cause  which  throws  the  abdominal  muscles  into  action 
produces  a similar  effect  on  the  musculus  testis;  which  circumstance 
appears  to  be  most  remarkable  in  the  young  subject.  When  we 
cough  or  act  with  the  abdominal  muscles,  we  find  the  testicles  to 
be  drawn  up;  the  musculus  testis  and  abdominal  muscles  taking  on 
the  same  action  from  the  same  cause.f 

“ At  this  time  of  life  the  testis  is  connected  in  a very  particular 
manner  with  the  parietes  of  the  abdomen,  at  that  place  where  in 
adult  bodies  the  spermatic  vessels  pass  out,  and  likewise  with  the 
scrotum.  This  connexion  is  by  means  of  a substance  which  runs 
down  from  the  lower  end  of  the  testis  to  the  scrotum,  and  which  at 
present  I shall  call  the  ligament,  or  gubernaculum  testis,  because 
it  connects  the  testis  witli  the  scrotum,  and  seems  to  direct  its 
course  through  the  rings  of  the  abdominal  muscles.  It  is  of  a 
pyramidal  form  ; its  large  bulbous  head  is  upwards,  and  fixed  to  the 
lower  end  of  the  testis  and  epididymis,  and  its  lower  and  slender 
extremity  is  lost  in  the  cellular  membrane  of  the  scrotum.  The 
upper  part  of  this  ligament  is  within  the  abdomen,  before  the  psoas, 
reaching  from  the  testis  to  the  groin,  or  to  where  the  testicle  is  to 
pass  out  of  the  abdomen  ; whence  the  ligament  runs  down  into  the 
scrotum,  precisely  in  the  same  manner  as  the  spermatic  vessels  pass 
down  in  adult  bodies,  and  is  there  lost.  The  lower  part  of  the 
round  ligament  of  the  uterus  in  a foetus  very  much  resembles  this 
ligament  of  the  testis,  and  may  be  plainly  traced  down  into  the 
labium,  where  it  is  imperceptibly  lost.  That  part  of  the  ligamentum 
testis  which  is  within  the  abdomen  is  covered  by  the  peritoneum 
all  round  except  at  its  posterior  part,  which  is  contiguous  to  the 
psoas,  and  connected  with  it  by  the  reflected  peritoneum  and  by  the 
cellular  membrane.  It  is  hard  to  say  what  is  the  structure  or  com- 
position of  this  ligament;  it  is  certainly  vascular  and  fibrous,  and 
the  fibres  run  in  the  direction  of  the  ligament  itself,  which  is  covered 
by  the  fibres  of  the  cremaster  or  musculus  testis,  placed  immediately 
behind  the  peritoneum.  This  circumstance  is  not  easily  ascertained 
in  the  human  subject;  but  is  very  evident  in  other  animals,  more 
especially  in  those  whose  testicles  remain  in  the  cavity  of  the  abdo- 
men after  the  animal  is  full  grown. 

“ In  the  hedgehog  the  testis  continue  through  life  to  be  lodged 
within  the  abdomen,  in  the  same  situation  as  in  the  human  foetus; 

* [The  first  lumbar  nerve,  which  gives  many  small  branches  to  the  transversalis 
abdominis,  sends  off  a branch  which,  in  conjunction  with  smaller  branches  from 
the  second  lumbar  nerve,  forms  the  ‘ external  spermatic  nerve’  from  which  the 
cremaster  is  supplied.] 

f [As  the  cremaster  is  supplied  from  common  or  spinal  nerves,  it  is  not  sur- 
prising that  it  should  in  some  cases,  like  the  occipito-frontalis  muscle,  be  under 
the  control  of  the  will.  Mr.  Marshall  observes,  in  his  work  On  Recruits,  “ Some 
individuals  have  the  voluntary  power  of  contracting  and  relaxing  the  cremaster 
muscle  : others  can  elevate  the  testicle  on  one  side  but  not  on  the  other;  and  1 
have  seen  a few  persons  who  could  voluntarily  raise  a testicle,  but  had  not  the 
pov/er  of  letting  it  return  into  the  scrotum.”] 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS. 


47 


and  they  are  fastened  by  the  same  kind  of  ligament  to  the  inside  of 
the  parietes  of  the  abdomen  at  the  groin.  Now  in  that  animal  I 
find  that  the  lowermost  fibres  of  the  internal  oblique  muscle,  which 
constitute  the  cremaster,  are  turned  inwards  at  the  place  where  the 
spermatic  vessels  come  out  in  other  animals,  making  a smootli  edge 
or  lip  by  their  inversion,  and  that  then  they  mount  up  on  the  liga- 
ment to  the  lower  end  of  the  testis.^  Sometimes  in  the  human 
body,  and  in  many  other  animals,  and  very  often  in  sheep,  the  testes 
do  not  descend  from  the  cavity  of  the  abdomen  till  late  in  life,  or 
never  at  all.  In  the  ram,  when  the  testis  is  come  down  into  the 
scrotum,  the  cremaster  is  a very  strong  muscle ; and,  though  it  be 
placed  more  inwards  at  its  beginning,  it  passes  down  pretty  much 
as  it  does  in  the  human  body,  and  is  lost  on  the  outside  of  the  tunica 
vaginalis;  but  in  the  ram,  whose  testis  still  remains  suspended  in 
the  abdominal  cavity,  I find  that  the  cremaster  still  exists,  tiiough 
it  is  a weaker  muscle;  and  instead  of  passing  downwards,  as  in  the 
former  case,  it  turns  inwards  and  upwards,  and  is  lost  in  the  peri- 
toneum that  covers  the  ligament  which  attaches  the  testis  to  the 
parietes  of  the  abdomen,  which  in  this  state  of  the  animal  is  about 
an  inch  and  a half  in  length.  In  the  human  foetus,  while  the  testis 
is  retained  in  the  cavity  of  the  abdomen,  the  cremaster  is  so  slender 
that  I cannot  trace  it  to  my  own  satisfaction,  either  turning  up 
towards  the  testis  or  turning  down  towards  the  scrotum.  Yet, 
from  analogy,  we  may  conclude  that  it  passes  up  to  the  testicle; 
since  in  the  adult  we  find  it  inserted  or  lost  on  the  lower  part 
of  the  tunica  vaginalis,  in  the  same  manner  as  in  the  adult 
quadruped.! 

“ The  peritoneum,  which  covers  the  testis  and  its  ligament  or 
gubernaculum,  is  firmly  united  to  the  surfaces  of  these  two  bodies; 
but  all  around,  to  wit,  on  the  kidney,  the  psoas,  the  iliacus,  internus, 
and  the  lower  part  of  the  abdominal  muscles,  that  membrane 

* [The  apparent  anomaly  of  this,  as  of  almost  every  other  natural  structure, 
disappears  when  we  attain  the  requisite  amount  of  knowledge  respecting  the 
conditions  under  which  it  exists.  The  testes  of  the  hedgehog,  like  those  of  the 
mole,  (see  p.  66,)  are  subject  to  remarkable  periodical  enlargement  at  the  season 
of  copulation,  when  they  are  drawn  down  by  the  cremaster  lo  the  external  ring. 
In  this  situation  they  are  favourably  placed  to  be  affected  by  the  expulsive  actions 
of  the  diaphragm  and  abdominal  muscles,  by  which  they  are  eventually  protruded 
and  the  cremasteric  pouch  is  inverted.  As  the  testes  diminish  in  size  their 
muscular  covering  contracts  upon  them  and  returns  them  into  the  abdomen.] 

f [By  such  a pre-arrangement  of  the  relations  of  the  cremaster  to  the  testis  the 
necessity  for  the  latter  to  overcome  in  its  passage  outwards  tlie  resistance  of  the 
inferior  fibres  of  the  transversalis  abdominis  and  obliquus  internus  is  obviated. 
It  cannot  reasonably  be  doubted  that  the  cremaster  exists,  as  such,  in  the  human 
foetus  prior  to  the  descent  of  the  testis,  since  Jt  is  indubitably  present  and  attached 
to  an  abdominal  testis  in  animals  where  no  mechanical  cause  could  have  operated 
to  produce  this  disposition  of  the  muscular  fibres.  Besides,  the  use  of  the 
cremaster  as  a supporter  and  compressor  of  the  testis  is  obviously  too  important 
for  such  a connexion  to  have  been  allowed  to  result  from  the  gland  accidentally, 
as  it  were,  pushing  before  it  some  opposing  fibres  of  the  abdominal  muscles  in 
its  progress  outwards,  as  Carus  imagines.  See  his  Comparative  Anatomy,  by 
Gore,  vol.  ii.,  p.  347.] 


48 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


adheres  very  loosely  to  all  the  surfaces  which  it  covers.  Where 
the  peritoneum  is  continued  or  reflected  from  the  abdominal  muscles 
to  the  ligament  of  the  testis  it  passes  first  downwards  a little  way, 
as  if  going  out  of  the  abdomen,  and  then  upwards,  so  as  to  cover 
more  of  the  ligament  than  is  within  the  cavity  of  the  abdomen.  At 
this  place  the  peritoneum  is  very  loose,  thin  in  its  substance,  and  of 
a tender  gelatinous  texture  ; but  ail  around  the  passage  of  that  liga- 
ment the  peritoneum  is  considerably  tighter,  thicker,  and  of  a more 
firm  texture.  When  the  abdominal  muscles  are  pulled  up  so  as  to 
tighten  and  stretch  the  peritoneum  this  membrane  remains  loose  at 
the  passage  of  the  ligament  while  it  is  braced  or  tight  all  around; 
and  in  that  case  the  tight  part  forms  a kind  of  border  or  edge  around 
the  loose  double  part  of  the  peritoneum,  where  the  testis  is  after- 
wards to  pass.  This  loose  part  of  the  peritoneum,  like  the  intro- 
suscepted  gut,  may,  by  drawing  the  testis  upwards,  be  pulled  up 
into  the  abdomen,  and  made  tight,  and  then  there  is  no  appear- 
ance of  an  aperture  or  passage  down  towards  the  scrotum ; but 
when  the  scrotum  and  ligament  are  drawn  downwards,  the  loose 
doubled  part  of  the  peritoneum  descends  with  the  ligament,  and 
then  there  is  an  aperture  from  the  cavity  of  the  abdomen  all  around 
the  fore  part  of  the  ligament,  which  seems  ready  to  receive  the 
testis.  This  aperture  becomes  larger  when  the  testis  descends 
lower,  as  if  the  pyramidal  or  wedge-like  ligament  was  first  drawn 
down  in  order  not  only  to  direct  but  to  make  room  for  the  testis 
which  must  follow  it.  In  some  foetuses  I have  found  the  aperture 
so  large  that  I could  push  the  testis  into  it  as  far  as  the  tendon  of 
the  external  oblique  muscle. 

“ From  this  original  situation  within  the  abdomen  the  testis  after- 
wards descends  to  its  destined  station  in  the  scrotum ; but  it  becomes 
difficult  to  ascertain  the  precise  time  of  this  descent,  as  we  hardly 
ever  know  the  exact  age  of  our  subject.  Accoi’ding  to  the  observa- 
tions which  I have  made,  it  seems  to  happen  sooner  in  some 
instances  than  in  others;  but  generally  about  the  eighth  month. 
In  the  seventh  month  I have  commonly  found  the  testis  in  the  abdo- 
men ; and  in  the  ninth  I have  as  commonly  found  it  in  the  upper 
part  of  the  scrotum.  The  descent  being  thus  early,  and  the  passage 
being  almost  immediately  closed,  are  the  principal  means  of  pre- 
venting the  hernia  congenita. 

“ At  the  before-mentioned  period  the  testis  moves  downwards  till 
its  lower  extremity  comes  into  contact  with  the  lower  part  of  the 
abdominal  parieles  : wflien  the  upper  part  of  the  ligament,  which 
hitherto  was  within  the  abdomen,  has  sunk  downwards,  it  lies  in  the 
passage  from  the  abdomen  to  the  scrotum,  and  in  that  which  is 
afterwards  to  receive  the  testis.  As  the  testicle  passes  out  it  in 
some  degree  inverts  the  situation  of  the  ligament  passing  down 
beyond  it;  what  was  the  anterior  surface  of  the  ligament  while  in 
the  abdomen,  now  becoming  posterior  and  composing  the  lower 
and  anterior  part  of  the  tunica  vaginalis,  on  which  the  musculus 
-testis  is  lost.  This  is  more  evident  in  those  animals  whose  testicles 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS. 


49 


can  readily  be  made  to  pass  up  from  the  scrotum  to  the  abdomen. 
The  place  where  the  ligament  is  most  confined,  and  where  the 
testis  meets  with  most  obstruction  in  its  descent,  is  the  ring  in  the 
tendon  of  the  external  oblique  muscle ; and  accordingly  I think  we 
see  more  men  with  one  testis  or  both  lodged  immediately  within 
the  tendon  of  that  muscle  than  who  have  one  or  both  still  included 
in  the  cavity  of  the  abdomen,  which  I shall  take  notice  of  hereafter. 

“ After  the  testis  has  got  quite  through  the  tendon  of  the  external 
oblique  muscle  it  may  be  considered  as  now  in  a w^ay  easily  to 
acquire  its  determined  station,  though  it  commonly  remains  for 
some  time  by  the  side  of  the  penis,*  and  only  by  degrees  descends 
to  the  bottom  of  the  scrotum ; and  when  the  testis  has  descended 
entirely  into  the  scrotum  its  ligament  is  still  connected  with  it,  and 
lies  immediately  under  it,  but  is  shortened  and  compressed. 

“ Having  now  given  an  account  of  the  original  situation  of  the 
testes,  of  the  time  of  their  descent  from  the  abdomen,  and  of  the 
route  which  they  take  in  their  passage  to  the  scrotum,  I shall  in 
the  next  place  describe  the  manner  in  which  they  carry  down  the 
peritoneum  with  them,  and  then  explain  how  that  membrane  forms 
tlie  tunica  vaginalis  propria  in  common,  and  the  sac  of  the  hernia 
congenita  in  some  bodies. 

“ While  the  testis  is  descending,  and  even  when  it  has  passed  into 
the  scrotum,  it  is  still  covered  by  the  peritoneum,  exactly  in  the 
same  manner  as  when  within  the  abdomen,  the  spermatic  vessels 
running  down  behind  the  peritoneum  there  as  they  did  wdien  the 
testis  lay  before  the  psoas  muscle  J that  lamella  of  the  peritoneum 
is  united  behind  with  the  testis,  the  epididymis,  and  the  spermatic 
vessels,  as  it  was  in  the  loins,  and  likewise  with  the  vas  deferens; 
but  the  testis  is  fixed  posteriorly  to  the  parts  against  which  it  rests, 
being  unconnected  and  loose  forwards,  as  while  it  remained  in  the 
abdomen.  In  coming  down,  the  testis  brings  the  peritoneum  with 
it;  and  the  elongation  of  that  membrane,  though  in  some  circum- 
stances it  be  like  a common  hernial  sac,  yet  in  others  is  very  dif- 
ferent. If  we  can  imagine  a common  hernial  sac  reaching  to  the 
bottom  of  the  scrotum,  covered  by  the  cremaster  muscle ; and  that 
the  posterior  half  of  the  sac  covers  and  is  united  with  the  testis, 
epididymis,  spermatic  vessels,  and  vas  deferens ; and  that  the  ante- 
rior half  of  the  sac  lies  loose  before  all  those  parts,  it  wdll  give  a 
perfect  idea  of  the  state  of  the  peritoneum,  and  of  the  testis  when 
it  comes  first  down  into  the  scrotum.  The  testis  therefore,  in  its 
descent,  does  not  fall  loose,  like  the  intestine  or  epiploon,  into  the 
elongation  of  the  peritoneum,  but  slides  down  from  the  loins,  carry- 
ing the  peritoneum  with  it ; and  both  that  and  the  peritoneum  con- 
tinue to  adhere,  by  the  cellular  membrane,  to  the  parts  behind 
them,  as  they  did  when  in  the  loins.  This  is  a circumstance  which 

* [This  is  the  permanent  situation  of  the  testis  in  the  Quadrumana,  in  which 
also,  as  in  the  human  fetus  at  the  period  above  mentioned,  the  tunica  vaginalis 
communicates  with  the  abdominal  cavity.] 

6 


50 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


I think  may  be  easily  understood,  and  yet  that  does  not  appear  to 
be  the  case ; for  I find  students  very  generally  puzzled  with  it, 
imagining  that  when  the  testis  comes  first  down  it  should  be  loose 
all  round,  like  a piece  of  the  gut  or  epiploon  in  a common  hernia. 
The  ductility  of  the  peritoneum,  and  its  very  loose  connexion  by  a 
slight  cellular  membrane  to  psoas  muscle,  and  all  the  other  parts 
around  the  testis,  are  circumstances  which  favour  its  elongation 
and  descent  into  the  scrotum  with  the  testis.” 

“ This  peculiarity  of  descent  often  takes  place  in  some  of  the  intes- 
tines; but  can  only  happen  in  those  which  have  adhesions  to  the 
loins.  This  I suspect  is  only  to  be  met  with  in  old  ruptures,  never 
happening  at  the  first  formation  of  the  hernial  sac,  in  which  the 
intestine  lies  ; and,  I should  suppose,  could  only  form  very  gradually. 
The  caecum  has  sometimes  been  found  to  have  descended  into  the 
scrotum,  and  to  have  brought  along  with  it  the  adhesions  through 
its  whole  course.  The  same  thing  has  happened  to  the  sigmoid 
flexure  of  the  colon  ; and  I have  found  the  whole  of  it  in  the  left 
side  of  the  scrotum,  with  its  adhesions  brought  down  from  the  loins. 
ISuch  hernias  cannot  be  reduced ; and  in  case  of  strangulation, 
which  may  be  brought  on  by  a fresh  portion  of  intestine  coming 
down,  are  not  to  be  treated  in  the  common  way  : the  sac  should  not 
be  opened,  but  the  stricture  divided,  and  the  newly  protruded  part 
reduced. 

“It  is  plain,  from  this  description,  that  the  cavity  of  the  bag,  or 
of  the  elongation  of  the  peritoneum,  which  contains  the  testis  in  the 
scrotum,  must  at  first  communicate  with  the  general  cavity  of  the 
abdomen  by  an  aperture  at  the  inside  of  the  groin.  That  aperture 
has  exactly  the  appearance  of  a common  hernial  sac  ; the  spermatic 
vessels  and  vas  deferens  lie  immediately  behind  it,  and  a probe 
passes  readily  through  it  from  the  general  cavity  of  the  abdomen 
down  Ito  the  bottom  of  the  scrotum.  And  if  this  process  of  the 
peritoneum  be  laid  open  through  its  whole  length  on  the  fore  part, 
it  will  be  plainly  seen  to  be  a continuation  of  the  peritoneum : the 
testis  and  epididymis  will  appear  at  the  lower  part  of  it,  and  the 
spermatic  vessels  and  the  vas  deferens  wall  be  found  covered  by  the 
posterior  part  of  the  bag  in  their  whole  course  from  the  groin  to  the 
testis. 

“ Thus  it  is  in  the  human  body  wdien  the  testis  is  recently  come 
down:  and  thus  it  is,  and  continues  to  be  through  life,  in  every 
quadruped  which  I have  examined  where  the  testis  is  in  the  scrotum ; 
but  in  the  human  body  the  communication  between  the  sac  and  the 
cavity  of  the  abdomen  is  soon  cut  off.  Indeed  I believe  that  the 
upper  part  of  the  sac  naturally  begins  to  contract  as  soon  as  the 
testis  has  passed  through  the  muscles;  which  opinion  is  grounded 
on  the  following  observation.  In  an  instance  where,  from  the  age 
of  the  foetus  and  from  every  other  mark,  it  was  probable  that  the 
testis  was  very  recently  come  down,  and  yet  the  upper  part  of  the 
sac  was  very  narrow,  I pushed  the  testis  upwards,  in  order  to 
see  if  it  could  be  returned.  The  attachments  of  the  testis  easily 
admitted  of  its  ascent,  and  so  did  the  aperture  in  the  tendon 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS. 


nl 


of  the  external  oblique  muscle  ; but  the  orifice  and  upper  end  of  the 
sac  would  not  by  any  means  admit  of  the  testis  being  passed  quite 
up  into  the  abdomen.  However  this  may  be,  the  upper  end  of  the 
sac  certainly  contracts  and  unites  first,  and  is  quite  closed  in  a very 
short  space  of  time,  for  it  is  seldom  that  any  aperture  remains  in  a 
child  born  at  its  full  time ; and  this  contraction  and  union  is  con- 
tinued downwards  till  it  comes  near  the  testicle,  where  this  disposi- 
tion does  not  exist,  leaving  the  lower  part  of  the  sac  open  or  loose 
through  life  even  in  the  human  subject,  and  forming  the  tunica 
testis  vaginalis  propria,  the  common  seat  of  a hydrocele.  Many 
cases  of  hydrocele  in  children  seem  to  prove  that  the  progress  of 
this  contraction  and  union  is  downwards  ; for  in  them  the  water 
commonly  extends  higher  up  the  chord  than  in  the  adult,  except  in 
those  of  a considerable  size;  yet  in  some  children  this  union  seems 
not  to  take  place  regularly,  being  interrupted  in  the  middle,  and 
producing  a hydrocele  of  the  chord  which  neither  communicates 
with  the  abdomen  nor  tunica  vaginalis  testis.  The  contraction  and 
obliteration  of  the  passage  appears  to  be  a peculiar  operation  of 
Nature,  depending  upon  steady  and  uniform  principles,  and  not  the 
consequence  of  inflammation  nor  of  anything  that  is  accidental  ; 
and  therefore,  if  it  is  not  accomplished  at  the  proper  time,  the  diffi- 
culty of  bringing  about  a union  of  the  parts  is  much  greater,  as  is 
seen  in  children  who  have  had  the  sac  kept  open  by  a turn  of  the 
intestine  falling  down  in  the  scrotum  immediately  after  the  testis. 
This  looks  as  if  Nature,  from  being  balked  when  she  was  in  the 
humour  to  do  her  work,  would  not  or  could  not  so  easily  do  it 
afterwards.  I shall  readily  grant  that  what  has  been  advanced  here 
as  a proof  of  the  doctrine  may  be  explained  upon  other  principles; 
but  this  at  least  is  certain,  that  the  closing  of  the  mouth  and  of  the 
neck  of  the  sac  is  peculiar  to  the  human  species  and  we  must 
suppose  the  final  intention  to  be  the  prevention  of  ruptures,  to  W'hich 
men  are  so  much  more  liable  than  beasts  from  their  erect  state  of 
body.” 

In  some  cases  the  aperture  of  the  sac  is  not  entirely  closed,  allow- 
ing a fluid  to  pass  dowm  and  form  a hydrocele  ; which  fluid,  upon 
pressure,  can  be  squeezed  back  into  the  belly  ; and  instances  of  this 
kind  sometimes  giving  the  idea  of  a gut  being  protruded,  make  it 
difficult  to  determine  the  exact  nature  of  the  case. 

“ What  is  the  immediate  cause  of  the  descent  of  the  testis  from 

* [The  chimpanzee,  or  African  orang-utan  (Simla  Treg-Zodyte,  Blum.),  which 
of  all  mammalia  approximates  most  closely  to  the  human  structure,  resembles 
man  in  the  early  obliterations  of  the  canal  which  leads  from  the  peritoneal  cavity 
to  the  tunica  vaginalis.  In  the  Indian  orang  (Simla  Satyrus,  Linn.),  on  the  con- 
trary, the  canal  of  communication  is  free.  This  difference  of  structure  relates 
doubtless  to  the  different  conditions  of  the  lower  extremities  in  these  otherwise 
closely  allied  quadrumana  : in  the  chimpanzee  they  are  proportionally  larger  and 
stronger,  the  leg  can  be  more  extended  on  the  thigh,  and  the  hip-joint  is  strength- 
ened by  a ligamentum  teres;  in  the  orang,  on  the  contrary,  the  lower  limbs  are 
freely  developed  as  organs  of  support,  but  have  great  extent  of  motion,  the  hip- 
joint  being,  like  the  shoulder-joint,  without  a round  ligament.] 


52 


HUNTER  ON  THE  ANIMAL  CCCONOMY. 


the  loins  to  the  scrotum  ? It  is  evident  that  it  cannot  be  the  com- 
pressive force  of  respiration  ; because  the  testis  is  commonly  in  the 
scrotum  before  the  child  has  breathed,  that  is,  the  effect  has  been  pro- 
duced before  the  supposed  cause  has  existed.  Is  the  testis  pulled 
down  by  the  cremaster  muscle  1 I can  hardly  suppose  that  it  is  ; 
because,  if  that  was  the  case,  I see  no  reason  why  it  should  not  take 
place  in  the  hedgehog,  as  well  as  in  other  quadrupeds  ; and  if  the 
musculus  testis  had  this  power  it  could  not  bring  it  lower  than  the 
ring  of  the  muscle. 

“ Why  do  the  testes  take  their  blood-vessels  from  such  distant 
trunks  ? Those  physiologists  who  have  puzzled  themselves  about 
the  solution  of  this  question  have  not  considered  that  in  the  first 
formation  of  the  body  the  testes  are  situated  not  in  the  scrotum  but 
immediately  below  the  kidneys;  and  that  therefore  it  was  very 
natural  that  their  blood-vessels  should  rise  nearly  in  the  same  manner 
as  those  of  the  kidneys,  but  a little  lower.*  The  great  length  of 
the  spermatic  vessels  in  the  adult  body  will  no  doubt  occasion  a 
more  languid  circulation,  which  we  may  suppose  was  the  intention 
of  nature. 

“ The  situation  of  the  testis  in  the  foetus  may  likewise  account 
for  the  contrary  directions  of  the  epididymis  and  of  the  vas  deferens 
in  adult  bodies,  though  these  two  in  reality  make  only  one  excretory 
canal.  In  the  foetus  the  epididymis  begins  at  the  upper  end  of  the 
testis ; and  it  is  natural,  considering  it  is  an  excretory  tube,  that  it 
should  run  downwards.  And  it  is  as  natural  that  tlie  rest  of  the 
tube,  which  is  called  vas  deferens,  should  turn  inwards  at  the 
lower  end  of  the  testis,  because  that  is  its  most  direct  course  to 
the  neck  of  the  bladder.  Thus  we  see  that  in  the  foetus  the  excre- 
tory duct  is  always  passing  downw'ards.  But  the  testis  is  directed 
in  its  descent  by  the  gubernaculurn,  which  is  firmly  fixed  to  the 
lower  parts  of  the  testis  and  epididymis,  and  to  the  beginning  of 

* [The  singular  course  of  the  recurrent  nerves  results  from  a similar  mechani- 
cal cause.  At  the  period  when  the  rudimentary  larynx  first  derives  its  nerves 
from  the  par  vagum,  the  head  and  trunk  are  not  separated  by  a neck,  the  trachea 
is  not  formed,  the  heart  is  situated  near  the  base  of  the  cranium,  and  the  branchial 
arteries  given  off  from  the  bulb  of  the  then  single  artery  pass  above  the  nerves 
in  question.  As  the  anterior  extremities  bud  forth,  the  brachial  jrlexuses  are  de- 
veloped and  the  neck  begins  to  elongate;  then  the  rings  of  the  trachea  are  suc- 
cessively added,  and  the  larynx,  which  before  was  close  to  the  heart,  is  carried 
upward,  and  the  recurrent  nerves,  restrained  by  tlieir  relations  to  the  arteries, 
which  are  now  converted  into  the  subclavian  on  the  right  side,  and  aortic  arch 
on  the  left,  become  proportionately  elongated.  The  recurrent  course  of  the  branch 
of  the  dental  nerve  which  supplies  the  pulp  of  the  incisor  in  the  porcupine  and 
other  Rodentia  is  exjrlicable  on  a similar  principle,  the  relative  position  of  the 
pulp  to  the  origin  of  its  nerve  being  gradually  changed  by  the  growth  of  the  jaw 
and  extension  of  the  tooth.  See  the  preparation  illustrating  this  fact  in  the 
Gallery  of  the  Hunterian  Museum,  No.  357  b. 

It  is  scarcely  necessary  to  observe  that  the  above  mechanical  explanation  of 
the  course  of  the  recurrent  nerves  leaves  the  question  of  the  final  cause  as  open 
as  before.  Mr.  Hunter,  after  giving  the  physical  cause  of  the  course  of  the 
spermatic  artery,  next  proceeds  to  inquire  into  the  intention  of  Nature  with  re- 
ference to  that  peculiarity.] 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS. 


53 


the  vas  deferens,  and  thence  must  keep  those  parts  invariably  in 
their  situation  with  respect  to  one  another : and  therefore  in  pro- 
portion as  the  testis  descends  the  vas  deferens  must  ascend  from  the 
lower  end  of  the  testis;  and  it  must,  from  the  passage  through  the 
abdominal  muscles  down  to  the  testis,  run  parallel  with  the  spermatic 
vessels. 

“ The  testis,  its  coats,  and  the  spermatic  chord  are  so  often  con- 
cerned in  some  of  the  most  important  diseases  and  operations  of 
surgery,  particularly  in  the  bubonocele  and  hydrocele,  that  their 
structure  has  been  examined  and  described  by  the  surgeons,  as 
well  as  by  the  anatomists,  of  every  age.  Yet  the  descriptions  of 
the  clearest  and  best  writers  upon  the  subject  differ  so  much  from 
one  another,  and  many  of  them  differ  so  much  from  what  is  obvious 
and  demonstrable  by  dissection,  as  to  render  it  difficult  to  account 
for  such  a variety  of  opinions.  The  very  different  state  of  the 
parts  in  the  quadruped  and  in  the  human  body,  no  doubt,  must 
have  occasioned  error  and  confusion  among  the  writers  of  more 
ancient  times,  when  the  parts  of  the  human  body  were  described 
from  dissections  and  observations  made  principally  upon  brutes : 
and  the  structure  of  parts,  which  are  peculiar  to  the  foetus,  having 
been  imperfectly  understood,  we  may  suppose,  has  likewise  con- 
tributed to  cause  perplexity  and  contradiction  among  authors. 

“ Baron  Haller,  in  his  Opuscula  Pathologica,  has  observed  that 
in  infants  the  intestine  sometimes  falls  down  into  the  scrotum  after 
the  testis,  or  along  with  it,  and  occasions  what  he  calls  the  hernia 
congenita.  In  such  a case  the  hernial  sac  is  formed  before  the  in- 
testine falls  down,  as  that  ingenious  anatomist  has  observed.  There 
are,  besides,  two  circumstances  peculiar  to  a rupture  of  this  kind, 
the  intestine  being  always  in  immediate  contact  with  the  testis,  and 
there  being  no  tunica  vaginalis  propria  testis.  The  structure  of  the 
parts  in  a fetus  explains  in  the  most  satisfactory  manner  both  these 
circumstances,  however  extraordinary  they  must  appear  to  a man 
who  has  only  been  accustomed  to  view  the  parts  in  subjects  of  a 
more  advanced  age;  and  indeed  it  is  so  clear  that  it  needs  no  illus- 
tration. It  should  be  observed,  however,  that  the  hernia  congenita 
may  happen  not  only  by  the  intestine  falling  down  to  the  testis 
before  the  aperture  of  the  sac  be  shut  up,  but  perhaps  afterwards; 
for  when  the  sac  has  been  but  recently  closed  it  seems  possible 
enough  that  violence  may  open  it  again. 

“ It  must  likewise  be  obvious  to  every  anatomist,  who  examines 
the  state  of  the  testis  in  children  of  different  ages,  that  the  mouth 
and  neck  only  of  the  sac  close  up,  and  that  the  lower  part  of  the 
sac  remains  loose  around  the  testis,  and  makes  the  tunica  vaginalis 
propria.  Whence  it  is  plain  that  this  tunic  was  originally  a part 
of  the  elongated  peritoneum ; and,  as  it  is  undoubtedly  the  seat  of 
the  true  hydrocele,  it  is  also  plain  that  the  hernia  congenita  and  the 
true  hydrocele  cannot  exist  together  in  the  same  side  of  the  scrotum. 
For  when  there  is  a hernia  congenita  there  is  no  other  cavity  than 

6* 


51 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


that  of  the  hernial  sac  ; and  that  cavity  communicates  with  the 
general  cavity  of  the  abdomen. 

“ The  observations  contained  in  the  two  last  paragraphs  occurred 
to  my  brother  upon  reading  Baron  Haller’s  Opuscula  Pathologica, 
and  gave  rise  to  my  inquiries  upon  this  subject.” — Medical  Com- 
mentaries, part  i.,  p.  83. 

Having  explained  the  situation  of  the  testicles  in  the  foetus,  and 
their  descent,  with  the  circumstances  attending  it,  I shall  next  con- 
sider the  cases  in  which  the  change  takes  place,  in  one  or  both 
testicles,  later  than  the  usual  or  natural  time.  And  having  re- 
marked the  consequences  of  this  descent  at  so  late  a period,  I shall 
take  notice  of  those  instances  in  which  the  testicles  never  pass  out 
of  the  abdomen. 

I have  said  that  the  early  descent  of  the  testicles,  and  closing  of 
the  mouth  of  the  sac,  by  usually  happening  before  birth,  prevent 
likewise  the  descent  of  any  part  of  the  abdominal  viscera  ; but 
when  the  testicles  remain  in  their  first  situation  beyond  this  period 
these  advantages  ai’e  lost;  a part  of  the  intestines  or  epiploon 
being,  under  these  circumstances,  liable  to  descend  along  with 
them. 

The  first  or  natural  process,  in  some  instances,  not  having  been 
begun,  or  having  been  interrupted  before  birth,  it  becomes  afterwards 
very  uncertain  when  the  descent  will  be  completed:  yet  I think  the 
completion  most  frequently  happens  between  the  years  of  two  and 
ten,  while  the  person  is  young,  and  growing,  being  seldom  delayed 
beyond  the  age  of  puberty. 

It  is  not  easy  to  ascertain  the  cause  of  this  failure  in  the- descent 
of  the  testicle;  but  I am  inclined  to  suspect  that  the  fault  originates 
in  the  testicles  themselves.  This  however  is  certain,  that  the  tes- 
ticle which  has  completed  its  descent  is  the  largest,  which  is  more 
evident  in  the  quadruped  than  in  the  human  subject ; as  in  these  we 
can  have  an  opportunity  of  examining  the  parts  when  we  please, 
and  can  determine  how  small  in  comparison  with  the  other  that 
testicle  is  which  has  exceeded  the  usual  time  of  coming  down ; it 
never  descends  so  low  as  the  other. 

The  descent  of  that  testicle  is  very  slow  which  is  not  completed 
before  birth,  often  requiring  years  for  that  purpose ; and  it  some- 
times never  reaches  the  scrotum,  especially  the  lower  part  of  it. 
There  is  oftener  I believe  an  inequalit}^  in  the  situation  of  the  two 
testicles  than  is  commonly  imagined,  being  seldom  equally  low  in 
the  scrotum ; and  I am  of  opinion  that  the  lowest  is  the  most  vigorous, 
having  taken  the  lead  readily,  and  come  to  its  place  at  once.  The 
part  where  it  meets  with  the  greatest  difficulty  in  its  descent  is  in 
the  division  of  the  tendon  of  the  external  oblique  muscle  called  the 
riftg. 

How  far  an  erect  position  of  body,  the  action  of  the  abdominal 
muscles,  and  the  effect  produced  upon  the  contents  of  the  abdomen 
in  breathing  may  contribute  mechanically  to  the  descent  of  the 
testicles  when  the  natural  operations  of  the  animal  oeconomy  have 


SITUATION  OF  THE  TESTIS  IN  THE  FOETUS. 


55 


failed,  I will  not  pretend  to  decide ; but  when  we  see  these  com- 
bined actions  producing  an  unnatural  descent  of  a portion  of  intes- 
tine, we  may  conceive  that  they  are  likewise  capable  of  contribu- 
ting to  the  descent  of  the  testicle. 

When  the  testicle  has  remained  in  the  cavity  of  the  abdomen 
beyond  the  usual  time,  it  is  impossible  to  say  whether  the  disposition 
for  closing  up  the  passage,  after  it  has  passed  out,  is  in  any  degree 
lost  or  not ; but  when  it  comes  dowm  afterbirth,  we  can  easily  sup- 
pose a portion  of  intestine  or  epiploon  is  more  likely  to  descend  and 
prevent  the  closing  of  the  mouth  of  the  sac,  than  before  the  child 
was  born,  when  certain  actions  had  not  taken  place.  We  should 
therefore  watch  this  descent  of  the  testicle,  and  endeavour,  by  art, 
to  procure  that  union  which  the  natural  powers  are  either  not  dis- 
posed to  perform,  or  are  prevented  from  completing  by  the  descent 
of  other  parts ; but  art  should  not  be  used  too  soon,  nor  till  the 
testicle  has  got  a little  way  below  the  ring.  As  this  progress  is  very 
slow,  especially  when  the  testicle  is  creeping  through  the  ring,  a 
doubt  often  arises  whether  it  is  better  entirely  to  prevent  its  passage, 
or  to  assist  it  by  exercise  or  other  means;  and  it  would  certainly 
be  the  best  practice  to  assist  it,  if  that  could  be  done  effectually  and 
safely.  When  it  has  got  upon  the  outside  of  the  tendon  it  can  in 
general  be  easily  pushed  up  again  into  the  abdomen  ; and  in  these 
two  situations  it  will  sometimes  play  backwards  and  forwards  for 
several  years,  without  ever  coming  low  enough  to  allow  of  the  use 
of  artificial  means  to  hinder  its  descent,  or  to  prevent  a rupture. 
In  this  case  it  becomes  difficult  to  determine  what  should  be  done  ; 
but,  from  wdiat  I have  seen,  I should  be  inclined  to  wait  the  descent, 
giving  it  every  assistance  in  my  power.  Indeed,  in  all  cases  I 
would  advise  w'aiting  with  patience,  for  in  most  of  those  which  I 
have  seen,  years  have  elapsed  from  the  first  appearance  of  the  tes- 
ticle under  the  ring  of  the  abdominal  muscle  before  it  has  reached 
that  situation  in  which  we  may  safely  apply  a truss.  I never  have 
perceived  that  any  inconvenience  has  arisen  from  w'aiting,  and  the 
danger,  if  there  is  any,  may  be  in  some  degree  avoided.  I have 
always  recommended  moderate,  not  violent  exercise. 

When  the  testicle  has  got  some  way  below  the  ring,  then  the  case 
is  to  be  treated  as  an  inguinal  hernia,  and  a truss  applied  upon  the 
ring;  taking  care  that  the  testicle  is  not  injured  by  it:  but  as  this 
generally  happens  at  too  early  a period  for  the  patients  themselves 
to  be  capable  of  attending  to  it,  the  surgeon  who  is  employed 
should  be  very  attentive,  and  those  in  wdtose  immediate  care  they 
are,  particularly  watchful,  that  no  inconvenience  is  produced  by  the 
truss.  I have,  how'ever,  known  a rupture  happen  in  a man  thirty 
years  old,  where  the  testicle  had  not  even  got  into  the  ring.  In  such 
a case  I think  a truss  should  be  immediateh'  applied  ; for  if  it  is 
thought  advisable  to  prevent  the  testicle  from  coming  down,  a truss 
is  equally  adapted  for  that  purpose,  as  for  hindering  the  descent  of 
an  intestine  where  there  is  an  hei  nial  sac. 

It  sometimes  happens  that  one  of  the  testicles  remains  in  the 


56 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


cavity  of  the  abdomen  through  life,  never  acquiring  the  disposition 
to  change  its  situation;  therefore  the  person  naturally  concludes 
that  he  has  only  one  testicle  ; and  it  can  only  be  known  that  he  had 
two  by  an  examination  of  these  parts  after  death;  it  is,  however, 
possible  that  in  some  instances  one  may  be  wanting;  but,  if  we  are 
to  reason  from  analogy,  we  must  suppose  this  to  be  a very  rare 
case  ; for  it  is  a very  common  circumstance,  that  many  quadrupeds 
have  only  one  testicle  in  the  scrotum  ; and  in  such  as  are  killed  for 
food,  and  I'rom  that  circumstance  come  more  particularly  under 
observation,  if  this  peculiarity  has  been  noticed,  we  in  general  find 
the  other  testicle  in  the  cavity  of  the  abdomen ; though  in  some 
instances  they  are  both  found  lying  in  that  cavity. 

When  one  or  both  testicles  remain  through  life  in  the  belly,  I 
believe  that  they  are  exceedingly  imperfect,  and  probably  incapable 
of  performing  their  natural  functions,  and  that  this  imperfection 
prevents  the  disposition  for  descent  from  taking  place.  That  they 
are  more  defective  than  even  those  which  are  late  in  passing  to  the 
scrotum,  is  to  be  inferred  from  w'hat  is  very  evident  in  quadrupeds, 
the  testicle  that  has  reached  the  scrotum  being  in  them  considera- 
bly larger  than  the  one  which  remains  in  the  abdomen.  It  is 
probable  that  this  peculiarity  is  a step  towards  the  hermaphrodite, 
the  testicle  being  seldom  well  formed.  I have  only  seen  one  case 
in  the  huinan  subject  where  both  testicles  continued  in  the  abdo- 
men; this  proved  an  exception  to  the  above  observation,  since  we 
are  led  to  conclude  that  they  were  perfectly  formed,  as  the  persons 
had  all  the  powers  and  passions  of  a man.*  In  such  cases  nothing 
is  to  be  done  by  art,  as  it  is  not  possible  to  give  the  testicles  the 
stimulus  of  perfection,  which  I believe  is  necessary  to  make  them 
assume  the  disposition  requisite  for  their  descent  ;j-  and  the  ring  of 
the  external  oblique  muscle  is  perhaps  less  liable,  in  such  instances, 
to  allow  a portion  of  intestine  to  push  down,  than  w'here  the  testi- 
cles have  passerl  through  it;  and  such  persons  may  probably  be 
more  secure  from  accidents  of  this  kind  than  if  they  had  been  more 
perfectly  formed.  ' 

The  testicle,  in  changing  its  situation,  does  not  always  preserve 
a proper  course  towards  the  scrotum,  there  being  instances  of  its 

* [It  spems  remarkable,  that  with  this  experience  Mr.  Hunter  should  have 
formed,  from  inconclusive  analogy,  and  promulgated  an  opinion  lending  to 
occasion  so  much  unhappiness  as  that  which  attributes  exceeding  imperfection, 
and  probable  incapacity  of  performing  their  natural  functions,  to  testes  which  in 
the  human  subject  are  retained  within  the  abdomen.  That  there  is  nothing  in 
such  a situation  which  necessarily  tends  to  impair  their  efficiency,  is  evident,  from 
the  number  of  animals  in  which  they  constantly  form  part  of  the  abdominal 
viscera.  And  in  those  in  which  the  testes  naturally  pass  into  a scrotum,  their 
continuance  in  the  abdomen,  according  to  our  author’s  own  observation,  is 
accompanied  only  with  a difference  of  size  or  shape  ; now  we  may  readily  sup- 
pose that  this  may  influence  the  quantity,  but  not  necessarily  the  quality  of  the 
secretion.] 

t [The  case  described  in  the  paper  on  the  vesiculas  seminales,  p.  Gl,  seems  to 
offer  an  exception  to  this  rule ; the  right  testicle  had  passed  through  the  external 
ring,  although  the  vas  deferens  was  impervious.] 


SITUATION  OF  THE  TESTIS  IN  THE  FCETUS. 


57 


taking  another  direction,  and  descending  into  the  peringeum.  How 
this  is  brought  about  is  difficult  to  say;  it  may  possibly  be  occa- 
sioned by  something  unusual  in  the  construction  of  the  scrotum  ; or, 
more  probably,  by  a peculiarity  in  that  of  the  perineeum  itself  ; for 
it  is  not  easy  to  imagine  how  the  testicle  could  make  its  way  to 
the  parts  about  the  perinaeum  if  these  were  in  a perfectly  natural 
state. 

The  first  instance  of  this  kind  that  occurred  to  me  was  the  child 
of  a shopkeeper  in  Oxford-street,  which  I visited,  in  company  with 
Dr.  Garthshore,  about  the  year  1775;  but  what  became  of  the 
patient  afterwards  I do  not  know.  I have  lately  been  consulted  in 
a similar  case,  by  Mr.  Hunt,  a surgeon,  at  Burford  in  Oxfordshire, 
whose  apprehensions  of  what  may  be  the  consequences  of  a testicle 
remaining  in  the  perinceum  appear  to  be  well  founded.  The  most 
effectual  method  of  obviating  these  will  probably  be  to  support  the 
testicle  in  a situation  near  the  groin,  by  the  application  of  a bandage 
that  may  hinder  its  descent  into  the  perineeum,  by  which  the  parts 
may  be  in  time  so  consolidated  as  to  retain  it  by  the  side  of  the 
scrotum. 

“ Dear  Sir, 

“ I take  the  liberty  of  writing  to  you,  in  consequence  of  having 
met  with  a lusus  naturae  of  a peculiar  kind,  in  the  son  of  a man  in 
this  neighbourhood. 

“ The  boy  is  about  twelve  months  old  : his  right  testicle  is  situated 
about  an  inch  below  the  termination  of  the  scrotum,  and  half  an 
inch  on  the  right  side  of  the  centre  of  the  rapha  perinaei,  where  a 
kind  of  pouch  is  formed  of  the  common  integuments,  without  the  least 
rugous  or  scrotal  appearance  on  its  surface.  It  is  perfectly  detached 
from  the  scrotum  ; nor  can  the  testis  or  spermatic  process  be  at 
any  time  felt  in  any  part  of  the  scrotum,  though  I can  readily  make 
the  testis  pass  from  its  situation  quite  up  into  the  groin  ; but  immedi- 
ately upon  removing  my  hand  the  testis  falls  down  into  its  pouch  ; 
and  I can  trace  the  spermatic  chord  from  the  body  of  the  testis  up 
to  the  ring,  running  about  a fourth  of  an  inch  on  the  right  side  of 
the  scrotum.  The  scrotum  on  each  side  appears  perfectly  formed,  and 
the  left  testis  is  hi  situ  naturali.  Now,  sir,  as  I conceive  this  peculiar 
conformation  maybe  attended  with  great  inconvenience  to  the  child 
when  he  comes  to  ride  on  horseback,  and  on  many  other  occasions, 
I beg  leave  to  request  your  opinion  upon  it,  with  respect  to  what 
ought  to  be  done  to  prevent  accidents,  which  must,  if  left  in  its 
present  situation,  often  occur. 

“ Burford,  Oxfordshire. 


[Signed]  Thomas  Hunt.” 


58 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


2.  OBSERVATIONS  ON  THE  GLANDS  SITUATED  BE- 
TWEEN THE  RECTUM  AND  BLADDER,  CALLED 
VESICULyE  SEMINAI.es. 

Those  bags,  in  the  male  of  some  animals,  which  are  situated  be- 
tween the  bladder  and  rectum,  and  commonly  called  ‘ vesiculae  serai- 
nales,’  have  been  considered  as  reservoirs  of  the  semen  secreted  by 
the  testicles,  in  the  same  manner  as  the  gall-bladder  is  supposed  to 
be  a reservoir  of  the  bile.  Physiologists  must  have  been  led  to 
form  this  opinion  from  observing  that  in  the  human  subject  their 
ducts  communicate  with  the  vasa  deferentia  before  their  termination 
in  the  urethra.  This  communication  was  supposed  to  allow  the 
semen,  when  not  immediately  wanted,  to  pass  into  the  bags  from 
the  vasa  deferentia  by  a species  of  regurgitation.  But  more  accurate 
observations  respecting  their  structure  and  contents  in  the  human 
subject,  and  on  corresponding  parts  in  other  animals  supposed  to 
answer  a similar  purpose,  joined  to  the  circumstance  of  their  not 
being  found  in  every  class,  induced  me  to  conclude  that  this  opinion 
was  erroneous.  To  throw  as  much  light  upon  this  subject  as 
possible  I made  a number  of  experiments,  and  availed  myself  of  every 
opportunity  which  offered  of  examining  whatever  could  in  any  way 
elucidate  the  point ; and,  from  what  I have  been  able  to  collect,  I 
think  it  will  appear  that  they  cannot  be  considered  as  reservoirs  of 
the  semen. 

To. proceed  regularly  with  my  investigation,  I shall  begin  by 
comparing  the  contents  of  these  vesiculte  with  the  semen  as  it  is 
emitted  from  the  penis  of  a living  man.  From  which  comparison 
it  will  appear  that  the  two  secretions  are  very  different  in  their 
sensible  properties  of  colour  and  smell;  and  although  the  semen 
which  constitutes  the  first  part  of  the  emission  is  evidently  different 
from  the  last,  yet  every  part  of  it  is  unlike  the  mucus  found  in  these 
vesicLilte. 

The  semen  first  discharged  from  the  living  body  is  of  a bluish 
white  colour,  in  consistence  like  cream,  and  similar  to  what  is  found 
in  the  vasa  deferentia  after  death  ; while  that  which  follows  is  some- 
what like  the  common  mucus  of  the  nose,  but  less  viscid.  The 
semen  becomes  more  fluid  upon  exposure  to  the  air,  particularly 
that  first  thrown  out ; which  is  the  very  reverse  of  what  happens 
to  secretions  in  general.  The  smell  of  the  semen  is  mawkish  and 
unpleasant,  exactly  resembling  that  of  the  farina  of  the  Spanish  chest- 
nut ; and  to  the  taste,  though  at  first  insipid,  it  has  so  much  pungency 
as,  after  some  little  time,  to  stimulate  and  excite  a degree  of  heat 
in  the  mouth.  But  the  fluid  contained  in  these  vesiculas  in  a dead 
body  is  of  a brownish  colour,  and  often  varies  in  consistence  in 
different  parts  of  the  bag,  as  if  not  well  mixed.  Its  smell  does  not 
resemble  that  of  the  semen,  neither  does  it  become  more  fluid  by 
being  exposed  to  the  air. 


GLANDS  CALLED  VESICUL^  SEMINALES. 


59 


It  may,  however,  be  answered  to  this  that  the  contents  of  the 
vesiculee  are  generally  found  in  a putrid  state,  and  have  by  that 
means  undergone  a change  in  their  sensible  properties.  But  the 
objection  is  readily  obviated  by  comparing  this  fluid  with  that  in  the 
vasa  deferentia  as  it  comes  from  the  testicles  of  the  same  dead 
body,  between  which  there  appears  to  be  no  resemblance. 

To  be  still  more  certain  of  the  nature  of  what  these  vesicute  con- 
tain than  was  possible  from  the  examination  of  bodies  which  had 
been  dead  some  time,  I took  an  opportunity  of  opening  a man,  im- 
mediately after  his  death,  who  had  been  killed  by  a cannon-ball. 
The  fluid  in  the  vesiculse  was  of  a ligiiter  colour  than  has  usually 
been  found  in  men  who  have  been  dead  a considerable  time ; but 
it  was  not  by  any  means  like  the  semen  either  in  colour  or  smell. 
In  another  man  who  died  instantaneously,  in  consequence  of  falling 
from  a considerable  height,  whose  body  I inspected  soon  after  the 
accident,  the  contents  of  the  vesiculse  were  of  a lightish  whey 
colour,  having  nothing  of  the  smell  of  semen,  and  in  so  fluid  a state 
as  to  run  out  on  cutting  into  them. 

I have  likewise  examined  with  attention  a mucus  which  some 
men  discharge  upon  straining  hard  while  at  stool,  or  after  throwing 
out  the  last  drops  of  urine,  an  action  which  requires  a considerable 
exertion  of  the  parts.  This  discharge  is  generally  called  a seminal 
weakness,  and  is  I believe  commonly  supposed  to  be  the  semen;* 
but  in  all  cases  of  this  kind  in  which  I have  been  consulted  it  nearly 
resembled  the  contents  of  the  vesiculre  in  the  dead  body,  though 
perhaps  not  quite  of  so  deep  a colour.  1 endeavoured  in  vain  to 
persuade  a gentleman  who  had  this  complaint  that  the  discharge 
was  not  seminal,  till  by  examining  his  own  semen  and  comparing 
it  with  that  mucus  he  w'as  convinced  of  the  difference.  This 
gentleman  had  the  power  of  emitting  the  semen  in  the  same  quan- 
tity as  usual  immediately  after  the  mucus  had  been  discharged, 
which  is  a further  proof  that  this  fluid  is  not  semen.f 

In  this  country  eunuchs  seldom  come  under  our  examination ; 
but  W'e  have  sometimes  opportunities  of  opening  the  bodies  of  those 
who  have,  in  consequence  of  disease  or  accident,  lost  one  or  both 
testicles;  and  several  subjects  of  this  kind  I have  inspected  after 
death.  Persons  who  have  had  one  testicle  taken  away  will  better 
illustrate  the  point  in  dispute  than  those  who  have  been  deprived  of 
both.  For  it  is  to  be  presumed  that  such  men  have  afterwards  had 
connexion  with  women,  and  consequently  had  the  action  of  emis- 
sion, which  must  have  emptied  the  vesicula  of  the  castrated  side,  if 
this  had  contained  semen  ; and,  as  it  could  not  be  replenished,  it 
should  have  been  found  empty  after  death.  We  have  also  in  such 
cases  an  opportunity  of  making  comparative  observations  between 

* Vide  Treatise  on  the  Venereal  Disease,  edit.  1st  and  2d,  p.  197.  [vol.  ii., 
p.  167  of  the  present  edition.] 

t The  discharge  was  truly  supposed  to  be  the  contents  of  the  vesiculte  ; and, 
it  being  imagined  that  these  contained  semen,  according  to  this  reasoning  the 
discharge  must  be  seminal. 


GO 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  vesicula  of  the  perfect  and  that  of  the  imperfect  side.  In  the 
eunuch  such  emissions  never  can  happen,  for  the  testicles  being 
gone  the  natural  and  leading  stimulus  is  lost;  therefore,  if  in  them 
the  vesiculas  were  found  full  after  death,  it  might  be  supposed  to  be 
the  semen  which  they  had  received  from  the  testicles  before  castra- 
tion that  had  remained  there  from  the  time  of  the  operation ; but 
castration  being,  in  such  cases,  usually  performed  on  children,  this 
circumstance  should  rather  be  considered  as  a proof  that  they 
secrete  their  own  mucus.  Yet  it  is  probable  the  vesiculae  will  nei- 
ther be  so  large  nor  so  full  in  eunuchs  as  in  the  perfect  man ; for  I 
am  of  opinion  that  they  are  connected  with  generation,  and  that  if 
the  constitution  is  deprived  of  that  power  these  bags  will  not  grow 
to  the  full  size.  But  where  only  one  testicle  is  removed  its  loss 
does  not  in  the  least  affect  generation,  therefore  does  not  produce 
any  change  in  the  vesicula  of  that  side  from  which  the  testicle  is 
taken  ; because  the  vesicula  does  not  depend  upon  the  testicle  for 
its  secretion,  but  upon  the  constitution,  and  on  the  person  being 
capable  of  the  act  of  generation  : therefore  as  one  testicle  is  suffi- 
cient to  preserve  manhood,  it  is  of  course  capable  of  keeping  up 
the  action  of  both  those  glands. 

A man  who  had  been  under  my  care,  in  St.  George’s  Hospital, 
for  a venereal  complaint,  died  there,  and  was  discovered  to  have 
lost  his  right  testicle.  From  the  cicatrix  being  hardly  observable 
it  must  have  been  removed  some  considerable  time  before  his  death; 
and  the  complaint  for  which  he  was  received  into  the  hospital  is  a 
convincing  proof  that  he  had  connexion  with  women  after  that 
period. 

I inspected  the  body  in  the  presence  of  Mr.  Hodges,  the  house- 
surgeon,  and  several  of  the  pupils  of  the  hospital.  Upon  dissecting 
out  and  examining  the  contents  of  the  pelvis,  with  the  penis  and 
scrotum,  I found  that  the  vas  deferens  of  the  right  side  was  smaller 
and  firmer  in  its  texture  than  the  other,  especially  at  that  end  next 
to  the  abdominal  rings,  near  to  the  part  which  had  been  cut  through 
in  the  operation.  The  cellular  membrane  surrounding  the  duct,  on 
the  right  side,  was  not  so  loose  as  on  the  left ; neither  were  the 
vessels  which  ramified  on  the  right  vesicula  so  full  of  blood.  But 
upon  opening  the  vesiculse,  both  appeared  to  be  filled  with  the  same 
kind  of  mucus,  and  similar  to  that  which  is  found  in  other  dead 
bodies  ; the  vesicula  of  the  right  side  being  rather  larger  than  that 
on  the  left.  Whatever,  therefore,  may  be  the  real  use  of  these 
vesiculae,  we  have  a proof  from  this  dissection  that  in  the  human 
subject  they  do  not  contain  the  semen. 

In  a man  who  died  in  St.  George’s  Hospital  with  a very  large 
bubonocele,  the  testicle  of  the  diseased  side  was  discovered  to  have 
almost  lost  its  natural  texture,  from  the  pressure  of  the  hernial  sac  ; 
and  upon  examiningthe  testicle  with  attention  there  was  no  appear- 
ance of  vas  deferens  till  we  came  near  the  bladder,  where  it  was 
almost  as  large  as  usual.  The  vesicula  of  that  side  was  found  to 
be  as  full  as  the  other,  and  to  contain  the  same  kind  of  mucus. 


GLANDS  CALLED  VESICUL^  SEMINALES. 


61 


I extirpated  the  left  testicle  of  a Frenchman,  who  was  a married 
man,  and  died  about  a year  afterwards,  having  been  extremely  il. 
for  several  months  before  his  death.  On  examining  the  body,  the 
vesiculse  were  both  found  nearly  full,  more  especially  that  on  the 
left  side,  which  might  be  accidental ; but  the  vas  deferens  of  the 
left  side,  where  it  lies  along  this  bag,  and  where  it  has  a similar 
structure  with  the  vesicute,  was  likewise  filled  with  the  same  kind 
of  mucus;  which  I believe  is  always  the  case,  whether  the  testicle 
has  been  removed  or  not. 

A young  man,  a coachman,  with  his  left  testicle  much  diseased, 
had  it  removed,  at  St.  George’s  Hospital,  by  Mr.  Walker,  in 
August  1785;  and  in  February  1786  he  returned  again  to  the  hos- 
pital, on  account  of  uncommon  pains  all  over  him.  For  these  he 
requested  to  be  put  into  the  warm  bath ; but  as  he  was  going 
from  the  W’ard  for  that  purpose,  he  dropped  down  almost  imme- 
diately. The  body  was  inspected,  with  a view  to  discover  the 
cause  of  his  death  ; and,  upon  examination  of  the  vesiculm,  the  bag 
of  the  left  side  was  as  full  as  that  on  the  right,  and  the  contents  in 
both  were  exactly  similar.  In  the  winter  1788  another  case  oc- 
curred nearly  resembling  the  above. 

In  dissecting  a male  subject,  in  the  year  1755,  for  a side  view  of 
the  contents  of  the  pelvis,  I found  a bag  on  the  left  side,  lying  con- 
tiguous to  the  peritonreum,  just  on  the  side  of  the  pelvis  where  the 
internal  iliac  vessels  divide  above  the  anajle  of  reflection  of  the 
peritonaeum  at  the  union  of  the  bladder  and  rectum.  The  left  vas 
deferens  was  seen  passing  on  to  this  bag ; and  what  is  very  singular, 
that  of  the  right,  or  opposite  side,  crossed  the  bladder,  near  its 
union  with  the  rectum,  to  join  it.  I traced  the  left  vas  deferens 
down  to  the  testicle ; but,  on  following  the  right  through  the  ring 
of  the  external  oblique  muscle,  I discovered  that  it  terminated  at 
once,  about  an  inch  from  its  passage  out  of  the  abdomen,  in  a blunt 
point,  which  was  impervious.  On  examining  the  spermatic  chord 
trom  this  point  to  the  testicle,  I could  not  find  any  vas  deferens  ; 
but,  by  beginning  at  the  testicle,  and  tracing  the  epididymis  from 
its  origin,  about  half-way  along  where  it  lies  upon  the  body  of  the 
testicle,  I perceived  that  it  at  first  became  straight,  and  soon  after 
seemed  to  terminate  in  a point.  The  canal  at  this  part  was  so 
large  as  to  allow  of  being  filled  with  quicksilver;  which,  however, 
did  not  pass  far,  so  that  a portion  of  the  epidid}'mis  was  wanting, 
and  likewise  the  vas  deferens  for  nearly  the  whole  length  of  the 
spermatic  chord  of  the  right  side.  On  the  left  side  the  vas  deferens 
began  where  the  epididymis  commonly  terminates,  and  there  was 
a deficiency  of  nearly  an  inch  of  the  extremity  of  the  epididymis. 
1 then  dissected  the  bag  above  mentioned,  which  proved  to  be  the 
two  vesiculae ; for,  by  blowing  air  from  one  vas  deferens,  I could 
only  inflate  half  of  it,  and  from  the  other  vas  deferens  the  other 
half.  They  contained  the  mucus  commonly  found  in  these  bags  ; 
but,  upon  the  most  accurate  examination,  I could  neither  discover 

7 


62 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


any  duct  leading  from  them  to  the  prostate  gland,  nor  the  remains 
of  one. 

It  was  evident  in  this  subject  that  there  was  no  communication 
between  the  vas  deferens  and  epididymis,  nor  between  these  bags 
and  the  urethra.  The  caput  gallinaginis  had  the  common  appear- 
ance, but  there  were  no  orifices  to  be  found.  The  testicles  were 
very  sound,  and  the  ducts  from  them  to  the  epididymis  were  very 
manifest  and  contained  semen.* 

From  these  circumstances  we  have  a presumptive  proof  that  the 
semen  can  be  absorbed  in  the  body  of  the  testicle  and  in  the  epididy- 
mis, and  that  the  vesiculse  secrete  a mucus  which  they  are  capable 
of  absorbing  when  it  cannot  be  made  use  of.  We  may  likewise 
infer  from  what  has  been  said  that  the  semen  is  not  I'etained  in  re- 
servoirs after  it  is  secreted,  and  kept  there  till  it  is  used,  but  that  it 
is  secreted  at  the  time  in  consequence  of  certain  affections  of  the 
mind  stimulating  the  testicles  to  this  action  ; for  we  find  that  if 
lascivious  ideas  are  excited  in  the  mind,  and  the  paroxysm  is  after- 
wards prevented  from  coming  on,  the  testicles  become  painful  and 
swelled  from,  we  may  suppose,  the  quantity  of  semen  secreted,  and 
the  increased  action  of  the  vessels,  which  pain  and  swelling  is  re- 
moved immediately  upon  the  paroxysm  being  brought  on  and  the 
semen  evacuated ; but  if  that  does  not  take  place,  the  action  of  the 
vessels  will  still  be  kept  up,  and  the  pain  in  the  testicle  in  general 
continue  till  the  paroxysm  and  evacuation  of  the  semen  is  brought 
on  to  render  the  act  complete,  without  w'hich  a stop  cannot  be  so 
quickly  put  to  the  action  of  the  vessels  that  produce  the  secretion, 
nor  the  parts  be  allowed  so  easily  to  resume  their  natural  state. 
There  is  at  this  time  no  sensation  of  any  kind  felt  in  the  seat  of  the 
vesiculse  seminales,  which  shows  that  the  action  is  in  the  testicles, 

* As  the  semen,  in  consequence  of  this  preternatural  formation  of  parts,  could 
not  be  conveyed  to  the  urethra  in  the  usual  way,  I conceived  it  possible  that 
there  might  be  another  unnatural  construction  to  make  up  for  the  deficiency  in 
the  vas  deferens,  and  therefore  examined  it  very  carefully  to  see  if  there  were  no 
supernumerary  vasa  deferenlia.  I was  led  to  do  this  more  particularly  from  often 
finding  parts  resembling  them  where  they  could  answer  no  kind  of  purpose.  By 
a supernumerary  vas  deferens  I mean  a small  duct  which  sometimes  arises  I'rom 
the  epididymis,  and  passes  up  the  spermatic  chord  along  with  the  vas  deferens, 
commonly  terminating  in  a blind  end,  near  to  wiiich  it  is  sometimes  a little  en- 
larged. I never  found  this  duct  go  on  to  the  urethra;  but,  in  some  instances, 
have  seen  it  accompany  the  vas  deferens  as  far  as  the  brim  of  the  pelvis.  There 
is  no  absolute  proof  that  this  is  a supernumerary  vas  deferens;  but  as  we  find 
the  ducts  of  glands  in  general  very  subject  to  singularities,  and  that  there  are  fre- 
quently supernumerary  ducts ; that  there  are  often  two  ureters  to  one  kidney, 
sometimes  distinct  from  beginning  to  end;  at  other  times  both  arising  from  one 
pelvis.  These  ducts,  arising  from  the  epididymis,  I am  inclined  from  analogy 
to  believe  are  of  a nature  similar  to  the  double  ureters.  They  resemble  the  vas 
deferens,  as  being  continuations  of  some  of  the  tubes  of  the  epididymis;  are 
convoluted  where  they  come  off  from  it;  afterwards  become  a straight  canal,  and 
passing  along  with  it  for  some  way,  they  are  then  most  commonly  obliterated. 

The  idea  of  their  being  for  the  purpose  of  returning  the  superfluous  semen  to 
the  circulation  must  certainly  be  erroneous,  from  their  being  so  seldom  met  with, 
and  so  very  seldom  continued  further  than  the  brim  of  the  pelvis. 


GLANDS  CALLED  VESICUL^  SEMINALES. 


6S 


and  in  them  alone.  The  pain  in  the  testicles,  in  consequence  of 
being  filled  with  semen  and  of  the  action  being  incomplete,  is  some- 
times so  considerable  as  to  make  it  necessary  to  produce  an  evacua- 
tion of  the  semen  to  relieve  the  patient. 

It  may  be  observed,  in  support  of  this  opinion,  that  these  bags 
are  as  full  of  mucus  in  bodies  much  emaciated,  where  the  person 
has  died  from  a lingering  disease,  as  in  those  of  the  strong  and 
robust,  whose  death  has  been  occasioned  by  violence  or  acute  dis- 
eases ; and  they  are  nearly  as  full  in  the  old  as  in  the  young ; which, 
most  probably,  would  not  be  the  case  if  they  contained  semen. 
These  facts,  taken  from  the  human  subject,  are,  I think,  sufficient  to 
establish  the  opinion  which  I have  laid  down;  but,  for  the  satisfac- 
tion of  others,  I shall  give  such  facts  and  observations  as  have  oc- 
curred in  my  dissection  of  different  animals  as  tend  to  clear  up  the 
point'in  question. 

These  vesiculse  are  not  similar  either  in  shape  or  contents  in  any 
two  genera*  of  animals  which  I have  dissected ; and  they  differ 
more  in  size,  according  to  the  bulk  of  the  animal,  than  any  other 
parts  whose  uses  in  diferent  animals  are  supposed  to  correspond; 
while  the  semen  in  most  of  those  which  I have  examined  may  be 
said  to  be  similar. 

The  resemblance  which  obtains  between  these  bags  and  the  gall- 
bladder in  the  human  subject  by  no  means  holds  equally  good  when 
applied  to  other  animals.  In  the  horse  they  are  like  twoj  small 
urinary  bladders,  almost  loose  and  pendulous,  with  a partial  coat 
from  the  peritonseum,  under  which  there  are  two  layers  of  muscular 
fibres;  they  are  thicker  in  their  coats  at  the  fundus  than  any  other 
part,  and  appear  there  to  be  glandular.  Their  openings  into  the 
urethra  are  very  large,  and  although  they  open  close  to  the  vasa 
deferentia  do  not  communicate  with  them.  The  septum  between 
the  two  ducts  is  not  continued  on  quite  to  the  urethra,  so  that  they 
cannot,  in  strict  language,  be  said  to  enter  that  passage  separately; 
but  there  is  not  length  of  common  duct  sufficient  to  admit  of  regur- 
gitation from  the  vasa  deferentia  into  these  bags.  They  are  not  of 
the  same  size  in  the  gelding  and  in  the  stone-horse,  being  large  in 
the  last.  Their  contents  in  both  are  exactly  similar,  and  nearly 
equal  in  quantity ; but  in  no  way  resembling  the  semen  emitted  by 
the  stone-horse  in  the  coitus,  or  what  is  found  in  the  vas  deferens 
after  death. 

In  the  boar  these  bags  ai’e  extremely  large,  and  divided  into 

* [This  term  is  here  used  in  a more  extended  sense  than  in  the  present  systems 
of  natural  history ; but  even  as  applied  to  the  Linnaean  genera  the  rule  is  affected 
by  numerous  exceptions  of  which  a comparison  of  the  vesiculae  seminales  of  the 
ape  with  those  of  the  human  subject  affords  a striking  example.] 

t [There  is  also  in  the  horse  a third  vesicula  seminalis,  of  a similar  structure  to 
the  two  lateral  ones,  between  which  it  is  situated,  and  having,  like  them,  no  com- 
munication with  the  vasa  deferentia.  This  want  of  correspondence  therefore 
between  the  number  of  the  vesiculee  and  that  of  the  testes  affords  another  argu- 
ment against  their  having  the  relations  to  each  other  which  exist  between  the 
gall-bladder  and  liver.] 


64 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


cells  of  a considerable  size  ; or  they  may  more  properly  be  said 
to  form  ramifications  closely  connected  with  one  another,  and 
having  a large  canal  or  duct  common  to  the  whole.  The  ducts 
contain  a whitish  fluid,  very  unlike  what  is  found  in  the  vasa 
deferenlia  of  the  same  animal,  with  which  they  have  not  the  least 
communication.^ 

In  the  rat  the  bags  are  large  and  flat,  with  serrated  edges,  and 
lie  some  way  within  the  abdomen,  containing  a thick  ash-coloured 
mucus,  nearly  of  the  consistence  of  soft  cheese ; very  diflerent  from 
what  is  found  in  the  vasa  deferentia  of  the  same  animal,  with  which 
they  do  not  communicate. 

, In  the  beaver  the  bags  are  convoluted  ; their  ducts  have  no  com- 
munication with  the  vasa  deferentia,  but  both  the  one  and  the  other 
open  on  the  verurnontanum. 

In  the  Guinea-pig  they  are  composed  of  long  cylindrical  tubes, 
and  lie  in  the  cavity  of  the  belly,  are  smooth  on  their  external 
surface,  and  do  not  communicate  with  the  vasa  deferentia.  They 
contain  a thick,  bluish,  transparent  substance,  which  is  softest  near 
the  fundus,  and  becomes  firmer  towards  the  openings  into  the  urethra, 
where  it  is  as  solid  as  common  cheese.  From  this  circumstance, 
and  what  is  observed  in  the  horse,  the  fundus  appears  to  be  the 
part  that  secretes  this  substance,  which  is  very  diflerent  in  colour 
and  consistence  from  the  contents  of  the  vasa  deferentia,  and  is 
often  found  in  broken  pieces  in  the  urethra. 

To  be  more  certain  that  the  substance  contained  in  these  bags 
was  not  the  secretion  of  the  testicle,  I extracted  one  of  the  testicles 
of  a Guinea-pig ; and  six  months  afterwards  gave  it  the  femalp.  As 
soon  as  the  action  of  copulation  was  over  (in  which  all  the  parts 
containing  semen  should  naturally  have  emptied  themselves)  I 
killed  the  animal,  and  upon  examination  found  the  vesicula  of  the 
perfect  side,  and  that  of  the  side  fi"om  which  the  testicle  had  been 
removed,  both  filled^with  a substance  in  every  respect  similar.  It 
will  scarcely  be  alleged  that,  this  substance  had  been  contained  in 
the  bag  before  the  extirpation  of  the  testicle  ; nor  could  it  be  semen, 
which  must  have  been  all  thrown  out  in  the  previous  connexion 
with  the  female. 

To  ascertain  that  the  contents  of  the  vesiculce  are  not  discharged 
into  the  vagina  of  the  female  with  the  semen  in  the  act  of  emission, 
I killed  a female  Guinea-pig  as  soon  as  the  male  had  left  her, 

* [Tyson  particul-arly  notices  the  glandular  structure  cf  the  vesiculae  seminales 
in  the  peccari  and  boar,  and  was  led  by  this  circumstance  to  the  same  opinion 
respecting  their  nature  and  use  as  Mr.  Hunter  is  endeavouring  to  establish  by  a 
more  extensive  and  various  induction  in  the  present  paper.  “John  van  Horn,” 
says  Tyson,  “ would  have  a threefold  matter  of  the  seed  : one  from  the  testes,  tlie 
second  from  the  vesiculaj  seminales,  and  a third  from  the  prostates.  But  this  De 
Graaf  strongly  opposes  ; and  will  admit  only  tliat  from  the  testes,  which  is  trans- 
mitted to  the  vesiculas  seminales,  but  not  at  all  bred  there.  Butin  our  subject,  and 
so  in  some  others,  they  being  glandulous,  they  must  therefore  secrete  some  juice  ; 
■which,  in  all  likelihood,  is  some  way  serviceable,  though  not  principally,  in  gener- 
ation.”— Inatomy  of  the  Mexico  Musk-hog,  Phil.  Trans.,  vol.  xiii.  p.  370,  1683.] 


GLANDS  CALLED  VESICUL.-E  SEMINALES. 


65 


and  examined  with  attention  what  was  contained  in  the  vagina 
and  uterus ; in  neither  could  I find  any  of  the  mucus  of  the  vesi- 
culee,  which  from  its  firmness  must  have  been  easily  detected. 

In  the  hedgehog  these  bags  are  very  large,  being  more  than 
twice  the  size  of  the  vesiculas  in  the  human  subject. 

Many  animals  have  no  such  bags;  and  I believe  they  are  want- 
ing in  the  greater  part  of  that  class  which  live  chiefly  upon  animal 
food  ; they  are,  however,  to  be  found  in  some  of  them,  and  the 
hedgehog  is  an  example.*  There  is  no  apparent  difference  in  the 
testicles,  vasa  deferentia,  or  semen  of  the  animals  which  have 
vesiculm  and  of  those  which  have  none ; and  the  mode  of  copula- 
tion, as  far  as  these  bags  can  be  concerned,  is  very  similar  in  both. 

In  birds,  as  far  as  I have  yet  observed,  there  is  nothing  analo- 
gous to  these  bags  ; and  yet  there  appears  to  be  no  difference  between 
the  mode  of  copulation  of  the  drake  and  the  bull  or  ram.  It  is 
very  natural  to  suppose  that  if  the  vesiculae  were  reservoirs  of 
semen  they  would  be  more  necessary  in  birds,  who  have  the  power 
of  repeating  the  act  of  copulation  in  an  infinitely  greater  degree 
than  quadrupeds ; and  indeed  we  find  that  in  birds  there  are  reser- 
voirs, which  may  account  for  this  power;  the  vasa  deferentia  being 
enlarged  just  before  they  open  into  the  rectum,  probably  to  answer 
that  intention.  As  birds  have  no  urethra,  some  having  merely  a 
groove,  as  the  drake  and  gander,f  and  many  being  even  without  a 
groove,  as  the  common  fowl,  it  was  absolutely  necessary  there 
should  be  such  a reservoir  somewhere ; and  the  necessity  of  this 
will  appear  more  evidently  by  and  by. 

What  I have  observed  of  the  reservoir  of  birds  is  equally  appli- 
cable to  amphibious  animals,  and  to  that  order  of  fish  called  rays. 

From  the  above  observations  I think  we  may  fairly  conclude  that 
these  vesiculae  are  not  for  the  purpose  of  containing  semen : the 
single  circumstance  of  their  ducts  being  united  to  those  of  the  tes- 
ticles in  the  human  subject  not  appealing  sufficient  to  set  aside  the 
many  facts  which  are  contradictory  to  such  an  opinion. 

Having  endeavoured  to  show  that  the  function  of  these  vesiculae 
has  hitherto  been  misunderstood,  the  following  observations  will 
tend  to  prove  that  they  are  subservient  to  generation,  though  their 
particular  use  is  not  yet  discovered  ; and,  for  the  better  understand- 
ing this  part  of  the  subject,  I shall  premise  the  following  facts. 

Animals  have  their  natural  feelings  raised  or  increased  accord- 
ing to  the  perfection  of  the  parts  connected  with  such  feelings  ; and 
the  disposition  for  action  is  also  in  proportion  to  the  state  of  the 

* [The  vesiculae  seminales  are  wanting  in  all  the  Ferae  with  the  exception  of 
the  Insectivora  ; also  in  the  Ruminants,  in  the  carnivorous  Cetacea,  and  in  all 
the  Marsupiata;  they  are  equally  wanting  in  the  insectivorous  Monotremata, 
which  of  all  mammiferous  animals  approximate  most  closely  to  the  oviparous 
Vertebrata.] 

f [After  repeated  examination,  we  find  the  structure  of  the  urethra  in  the  drake 
to  be  as  here  described,  viz.,  a groove,  and  not  a complete  canal,  as  represented 
by  Sir  Everard  Home.  See  Phil.  Trans.  1802,  p.  361,  pi.  xii.] 

7* 


66 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


parts  and  the  excitement  of  such  feelings.  But,  that  these  feelings 
may  be  duly  excited,  it  is  necessary  that  the  animal  and  the  parts 
should  be  healthy,  in  good  condition,  and  in  a certain  degree  of 
warmth  suitable  to  that  class  to  which  the  animal  belonss.  In  the 

O 

greatest  part  of  the  globe  there  is  a difference  in  the  warmth  of 
the  same  district  at  different  periods,  constituting  the  seasons ; and 
the  cold  in  some  of  them  is  so  considerable  as  to  prevent  those 
feelings  or  dispositions  in  animals  from  taking  place,  and  to  render 
them,  for  the  time,  unfit  for  the  purposes  of  generation.*  This  is 
owing  to  the  testicles  becoming  at  this  season  small,  and  being  there- 
fore unfit  to  give  such  dispositions,  as  is  the  case  in  very  young 
animals.  This  fact  is  very  obvious  in  birds,  of  which  the  sparrow 
may  be  produced  as  a proof.  For  if  a cock-sparrow  is  killed  in 
the  winter,  before  the  days  have  begun  to  lengthen,  the  testicle  will 
be  found  very  small ; but  if  that  organ  is  examined  at  different  times 
in  other  sparrows,  as  the  warmth  of  the  weather  increases,  and  if 
this  examination  is  continued  to  the  breeding-season,  the  difference 
in  the  size  of  the  testicle  will  be  very  striking.  This  circumstance 
is  not  peculiar  to  birds,  but  is  common,  as  far  as  I yet  know,  to 
all  animals  which  have  their  seasons  of  copulation.  In  the  buck 
we  find  the  testicles  are  reduced  to- a very  small  size  in  the  winter  ; 
and  in  the  land-mouse,  mole,  &c.,  this  diminution  is  still  more 
remarkable.  Animals,  on  the  contrary,  which  are  not  in  a state 
of  nature  have  no  such  change  taking  place  in  their  testicles ; and, 
not  being  much  affected  by  seasons,  are  consequently  always  in 
good  condition,  or  in  a state  to  which  other  animals  that  are  left  to 
themselves  can  only  attain  in  the  warmer  season.  Thei'efore  in 
man,  who  is  in  the  state  we  have  last  described,  the  testicles  are 
nearly  of  the  same  size  in  winter  as  in  summer  ; and  nearly,  though 
not  exactly,  the  same  thing  may  be  observed  in  the  horse,  ram,  &c., 
these  animals  having  their  seasons  in  a certain  degree. 

The  variation  above  taken  notice  of  is  not  confined  to  the  testicles, 
but  also  extends  to  the  parts  which  are  connected  with  them.  For 
in  those  animals  that  have  their  seasons  for  propagation  the  most 
distinctly  marked,  as  the  land-mouse,  mole,  &c.,  the  vesiculse  are 
hardly  discernible  in  the  winter,  but  in  the  spring  are  very  large, 
varying  in  size  in  a manner  similar  to  the  testicle.  It  may,  however, 
be  alleged  that  the  change  in  these  bags  might  naturally  be  supposed 
to  lake  place,  even  admitting  them  to  be  seminal  reservoirs  ; but 
what  happens  to  the  prostate  gland,  which  has  never  been  supposed 
to  contain  semen,  will  take  ofi'  the  force  of  this  objection,  since  in 
all  the  animals  which  have  such  a gland  (and  which  have  their 
season  for  propagation)  it  undergoes  a similar  change.  In  the  mole 
the  prostate  gland  in  winter  is  hardly  discernible,  but  in  the  spring 
becomes  very  large  and  is  filled  with  mucus. 

* It  is  not  required  that  the  season  for  the  copulation  of  different  animals 
should  be  equally  warm  ; for  the  frog  copulates  in  very  cold  weather,  while  the 
snake  and  lizard,  which  are  also  cold,  sleeping  animals,  do  not  copulate  till  the 
season  is  warm. 


GLANDS  CALLED  VESICUL^  SEMINALES. 


67 


From  these  observations  it  is  reasonable  to  infer  that  the  use  of 
the  vesiculse  in  the  animal  oeconomy  must,  in  common  with  many 
other  parts,  be  dependent  upon  the  testicles.  For  the  penis,  urethra, 
and  all  the  parts  connected  with  them,  are  so  far  subservient  to  the 
testicles  that  I am  persuaded  few  of  them  would  have  existed  if 
there  had  been  no  testicles  in  the  original  construction  of  the  body;* 
and  these  would  have  been  so  formed  as  merely  to  assist  in  the  ex- 
pulsion of  the  urine.  To  illustrate  this  opinion,  let  us  observe  what 
is  the  difference  between  these  parts  in  the  perfect  male  and  in  a 
male  that  has  been  deprived  of  the  testicles  wdien  very  young,  at 
an  age  in  which  they  have  had  no  such  influence  upon  the  animal 
(economy  as  to  affect  the  growth  of  the  other  parts.  In  the  perfect 
male  the  penis  is  large ; the  corpora  cavernosaf  being  capable  of 
dilatation.  The  corpus  spongiosum  is  very  vascular  ;j  that  part  of 
the  canal  which  is  called  the  bulb  is  considerably  enlarged,  form- 
ing a cavity;  and  the  musculi  acceleratores  urinre,  as  they  are 
termed,  are  strong  and  healthy.  In  many  animals  which  have  a 
long  penis,  the  muscular  fibres  are  continued  forwards  to  the  end 
of  it;  and  in  others,  though  not  extended  so  far,  they  are  very 
large. 

On  the  contrary,  in  the  castrated  animal  the  penis  is  small,  and 
not  capable  of  much  dilatation  ; the  corpus  spongiosum  is  less  vas- 
cular; the  cavity  at  the  bulb  is  a little  larger  than  the  canal  of  the 
urethra;  and  the  muscles  are  white,  small,  and  have  a ligamentous 

* [The  construction  and  functions  of  the  penis  in  reptiles  and  those  birds  which . 
possess  the  organ  prove  the  correctness,  of  this  view;  and  very  striking  evidence 
of  the  exclusive  relation  of  the  penis  to  the  functions  of  the  testes  is  afforded  by 
the  discoveries  in  natural  history  which  have  been  made  since  the  time  of  Hunter. 
Thus,  in  those  remarkable  Australian  quadrupeds,  the  Ornithorhynchus  and 
Echidna,  which  form  the  passage  from  the  mammiferous  to  the  oviparous  verte- 
brates, the  penis,  although  perforated  through  its'whole  extent,  does  not  carry 
off  the  urine,,  which  escapes  by  the  cloaca,  but  the  urethra  is  destined  solely  for 
tne  passage  of  the  fecundating  fluid  during  the  time  of  the  coitus.] 

t The  cells  of  the  corpora  cavernosa  are  muscular,  although  no  such  appearance 
is  to  be  observed  in  men  ; for  the  penis  in  erection  is  not  at  all  times  equally' 
distended.  The  penis  in  a cold  day  is  not  so  large  in  erection  as  in  a warm  one ; 
which,  probably,  arises  from  a kind  of  spasm  that  could  not  act  upon  it  if  it  were 
not  muscular. 

In  the  horse  the  parts  composing  the  cells  of  the  penis  appear  evidently 
muscular  to  the  eye;  and  in  a horse  just  killed  they  contract  upon  being  stimu- 
lated. 

j:  It -may  not  be  improper  to  observe,  that  the  corpus  spongiosum  urethrs  and 
glans  penis  are  not  spongy'  or  cellular,  but  made  up  of  a plexus  of  veins.  This 
structure  is  discernible  in  the  human  subject,  but  much  more  distinctly  seen  in 
many  animals,  as  the  horse,  &c. 


^ [The  disposition  of  the  muscular  fasciculi  of  this  part  is  chiefly  longitudinal, 
interlacing  in  an  undulating  manner  with  the  transverse  tendinous  fibres.  They 
are  most  numerous  near  the  termination  of  the  corpora  cavernosa,  and  gradually 
diminish  as  they  approach  the  origin.  When  examined  with  a high  magnifying 
power  the  ultimate  fibres  of  these  fasciculi  exhibit,  but  in  a fainter  degree,  the 
transverse  striae  characteristic  of  the  voluntary  muscular  fibre.] 


G8 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


appearance.  The  same  observations  ai’e  true,  if  applied  to  the 
erectores  penis. 

The  penis  of  the  perfect  male  is  of  a sufficient  length,  when 
erected,  to  reacli  to  the  farther  end  of  the  vagina  of  the  female.  In 
the  castrated  animal  it  is  much  shorter,  and  erections  having  then 
become  unnecessary,  the  parts  which  should  project  often  adhere 
to  the  inside  of  the  prepuce.  The  erectores  muscles  in  the  perfect 
male  are  strong  enough  to  squeeze  at  once  the  blood  out  of  the 
crura  into  the  body  of  the  penis,  so  as  to  straighten  and  contract 
the  urethra  instantaneously,  and  the  acceleratores  urinee*  have 
sufficient  pow'er  to  throw  out  the  semen  that  is  gradually  accumu- 
lated at  the  bulb  for  ejection. 

The  prostate  gland, f Cowper’s  glands,  and  the  glands  along  the 
urethra  (of  which  the  lacunas  are  the  excretory  ducts),  are  in  the 
perfect  male  large  and  pulpy,  secreting  a considerable  quantity  of 
slimy  mucus,  which  is  salt  to  the  taste ; it  is  most  probably  for  the 
purpose  of  lubricating  those  parts,  and  is  only  thrown  out  when  in 
vigour  for  copulation  : W’hile  in  the  castrated  animal  these  are  small, 
flabby,  tough,  and  ligamentous,  and  have  little  secretion.  From 
this  account  there  appears  to  be  an  essential  diflerence  between 
the  parts  connected  with  generation  of  the  perfect  male,  and  those 
which  remain  in  one  that  has  been  castrated,  more  especially  if  that 
operation  had  been  performed  while  the  animal  was  young. 

If  it  is  objected  that  the  same  changes  did-not  take  place  in  the 
men  from  whom  one  testicle  had  been  removed,  it  may  be  answered, 
that  the  operation  was  performed  late  in  life  : and  one  testicle 
being  left,  that  was  sufficient  to  carry  on  the  necessary  actions, 
and  consequently  to  preserve  the  powers;  therefore  whatever  parts 

* I shall  call  these  muscles  ‘expiilsores  seminis,’  as  I apprehend  their  real 
use  to  he  for  the  expulsion  of  that  secretion : these  muscles,  likewise,  throw  out 
tliose  drops  of  urine  which  are  collected  in  the  bulb  from  the  last  contractions  of 
the  bladder,  and  they  have  been,  from  this  circumstance,  named  acceleratores 
iirina;;  but  if  a receptacle  had  not  been  necessary  for  the  semen,  those  muscles 
had  probably  never  existed,  and  the  last  drops  of  urine  would  have  been  thrown 
out  by  the  action  of  the  bladder  and  urethra,  as  in  some  measure  is  the  case  in 
the  castrated  animal.  That  the  urethra  has  the  power  of  contraction  is  evident 
upon  the  application  of  any  stimulus,  for  I have  seen  the  urethra  refuse  to  allow 
an  injection  to  pass  on;  and  in  that  part  where  the  injection  stopped,  a fulness 
was  felt,  which  terminated  at  once:  this  contraction  is  most  probably  in  the 
internal  membrane;  it  also  will  often  refuse  the  passage  of  a bougie. 

I The  prostate  gland  is  not  common  to  all  animals.  It  is  wanting  in  the  bull, 
buck,  ami  most  probably,  I believe,  in  all  ruminating  animals.  In  this  class  the 
coats  of  the  vesiculee  are  much  thicker  and  more  glandular,  than  in  those  which 
have  prostate  glands;  it  is  therefore  natural  to  suppose  that  the  vesiculai  answer 
nearly  the  same  purposes  as  the  prostate  gland. a 

The  prostate  gland,  and  Cowper’s  glands,  as  well  as  the  vesiculffi,  are  wanting 
in  birds,  in  the  amphibious  animals,  and  in  those  fish  which  have  testicles,  as  all 
of  the  ray  kind. 


^ [The  glands  in  Ruminants  here  termed  ‘ vesiculae,’  are  now  regarded  as  a 
bifid  prostate.] 


GLANDS  CALLED  VESICUL^  SEMINALES. 


69 


had  a connexion  with  these  powers,  would  still  have  the  stimulus  of 
perfection  given  to  them. 

The  different  appearance  of  the  bulb  and  the  muscles  would  seem 
to  point  out,  in  the  perfect  male,  the  enlargement  of  the  bulb  to  be 
for  the  purpose  of  a receptacle  for  the  semen  ; for  although  I have 
denied  the  vesiculm  to  be  reservoirs,  yet,  as  it  was  necessary  that 
the  semen  should  be  accumulated  somewhere  before  ejection,  I shall 
endeavour  to  prove,  from  the  mode  of, copulation  in  the  anim.als  we 
are  best  acquainted  with,  that  the  bulb  is  intended  for  that  purpose. 
Let  us,  therefore,  give  a short  account  of  the  different  parts  con- 
cerned in  coition  ; and  by  observing  the  dependence  which  they  have 
upon  one  another,  see  how  this  proof  will  come  out. 

The  erection  of  the  penis  is  produced  by  a stop  being  put  to  the 
returning  blood,  and  this  stoppage  is  so  complete,  that  no  mechani- 
cal pressure  applied  to  the  body  of  the  penis  can  force  the  blood 
on  into  the  veins.  This  erection  answers  two  purposes ; it  gives 
size  and  strength  to  the  penis,  and  it  renders  the  canal  of  the  urethra 
smaller.  The  corpus  spongiosum  of  the  urethra  and  the  glans, 
which  is  only  a continuation  of  it,  are  filled  with  blood  from  the 
same  cause,  but  not  so  completely  as  the  body  of  the  penis,  since  from 
them  it  can  be  forced  out  into  the  veins  by  pressure.*  This  accu- 
mulation of  blood  in  the  corpus  spongiosum  diminishes  the  canal  of 
the  urethra  so  much,  that  any  pressure  upon  one  part  of  it  will  have 
a considerable  effect  upon  the  other  ';  not  only  by  lessening  its  capa- 
city at  the  part  pressed,  but  by  forcing  the  blood  forward,  the  parts 
beyond  will  be  still  more  distended,  and  consequently,  the  canal  of 

* In  April  17G0,  in  tlie  presence  of  Mr.  Blount,  I laid  bare  the  penis  of  a dog, 
almost  through  its  whole  length  ; traced  the  two  veins  that  came  from  the  glans 
(which  in  this  animal  makes  the  largest  part  of  the  penis),  and  separated  them 
from  the  arteries  by  dissection,  that  I might  be  able  to  compress  them  at  pleasure 
without  affecting  the  arteries.  I then  compressed  the  two  veins,  and  found  that 
the  glans  and  large  bulb  became  full  and  extended;  but  when  I irritated  the 
veins,  in  order  to  see  if  there  was  any  power  of  contraction  in  tliem  which 
might  occasionally  stop  the  return  of  the  blobd,  no  such  appearance  could  be 
observed. a 


a [From  this  experiment,  it  is  obvious  that  Hunter  regarded  the  stoppage  of 
the  circulation  through  the  veins  as  being  produced  by  external  compression. 
Douglas  (^Myographise  Comparatie  Specimen,  p.  9),  had  previously  described  the 
muscles  which  compress  the  vena  dorsalis  penis  in  the  dog;  and  Cowper  had 
more  fully  and  particularly  detailed  the  structure  and  actions  of  the  muscles 
which  have  a corresponding  office  in  the  opossum,  observing  that  “the  muscles 
of  the  cavernous  bodies  of  the  penis  of  this  creature,  having  no  connexion  with  the 
os  pubis,  cannot  apply  the  dorsum  penis  to  the  last-named  bone,  and  compress 
the  vein  of  the  penis,  whereby  to  retard  the  refluent  blood  and  cause  an  erection, 
as  we  have  observed  in  other  creatures ; but  some  large  veins  of  the  penis  here 
take  a different  course,  and  pass  through  the  middle  parts  of  the  bulb,  and  are 
only  liable  to  compression  made  by  the  intumescence  of  the  muscles  C C (mus- 
cles of  the  bulb)  that  inclose  them.  “But  the  chief  agent  in  continuing  the 
erection  of  the  penis  in  this  animal  is  the  sphincter  muscle  of  its  anus,  or  rather 
cloaca;  and  not  only  the  sphincter  muscle  of  the  cloaca  of  the  male  opossum, 
but  that  of  the  female  also  closely  embraces  the  penis  in  coition,  and  effectually 
retard  the  refluent  blood  from  its  corpora  cavernosa,  by  compressing  the  veins  of 
the  penis.”  (Phil.  Trans.,  vol.  xxiv.  1704,  p.  1584.)] 


70 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


the  urethra  be  in  that  proportion  diminished.  The  semen,  in  the 
time  of  copulation,  in  such  animals  as  remain  long  in  that  act,  is 
gradually  squeezed  along  the  vasa  deferentia  (as  it  is  secreted)  into 
the  bulb ; and  when  the  testicles  cease  to  secrete,  the  paroxysm, 
which  is  to  finish  the  whole  operation,  comes  on.  The  semen  acting 
as  a stimulus  to  the  cavity  of  the  bulb  of  the  urethra,  the  muscles 
of  that  part  of  the  canal  are  thrown  into  action;  the  fibres  nearest 
the  bladder,  probably,  act  first,  and  those  more  forward  in  quick 
succession;  the  semen  is  projected  with  some  force ; the  blood  in 
the  bulb  of  the  urethra  is  by  the  same  action  squeezed  forward,  but 
requiring  a greater  impulse  to  propel  it,  is  rather  later  than  the 
semen,  on  which  it  presses  from  behind  ; the  corpus  spongiosum 
being  full  of  blood,  acts  almost  as  quick  as  undulation,  in  which  it 
is  assisted  by  the  corresponding  constriction  of  the  urethra,  and  the 
semen  is  hurried  along  with  a considerable  velocity.* 

From  the  facts  which  I have  stated  respecting  the  organs  of 
generation,  the  observations  which  I have  made,  and  the  series  of 
actions  which  I have  considered  as  taking  place  in  the  copulation 
of  animals,  I think  the  following  inferences  may  be  fairly  drawn. 

That  the  bags,  called  vesiculfe  seminales,  are  not  seminal  reser- 
voirs, but  glands  secreting  a peculiar  mucus;  and  that  the  bulb  of 
the  urethra  is,  properly  speaking,  the  receptacle  in  which  the  semen 
is  accumulated  previous  to  ejection. 

Although  it  seems  to  have  been  proved  that  the  vesiculae  do  not 
contain  the  semen,  I have  not  been  able  to  ascertain  their  particular 
use  ; we  may,  however,  be  allowed  upon  the  whole  to  conclude  that 
they  are,  together  with  other  parts,  subservient  to  the  purposes  of 
generation. 


3.  ACCOUNT  OF  THE  FREE-MARTIN. 

Generation,  from  a seed,  requires  the  concurrence  of  two  causes 
to  give  it  perfection : the  one  to  form  -the  seed,  the  other  to  give  it 
the  principle  of  action.j 

* [Besides  the  functions  here  assigned  to  the  bulh  of  the  urethra,  in  relation  to 
the  reception  and  propulsion  of  the  semen,  we  may  also  notice  its  uses  in  reference 
to  the  distention  of  the  glans  penis,  of  which  Cowper,  in  his  description  of  the 
male  organs  of  the  opossum  above  quoted,  gives  a remarkable  example.  He 
observes  ; “ As  the  bulb  of  the  urethra  in  man  is  framed  for  the  use  of  the  glans, 
to  keep  it  sufficiently  distended  when  required,  so  it  seems  it  is  necessary  to  have 
two  of  these  bulbs  inclosed  with  their  particular  muscles  in  this  animal,  to  main- 
tain the  turgescence  of  its  double  or  forked  glans  when  the  penis  is  erected.” 
(^Phil  Trans.,  vol.  xxiv.,  1704,  p.  1585.)] 

I Tt  may  be  necessary  for  some  of  my  readers  to  have  explained  to  them  what 
I mean  by  a seed.  I do  suppose  that  the  word  seed  was  first  applied  to  grain,  or 


OF  THE  FREE-MARTIN. 


71 


The  cause  forming  the  seed  is  called  the  female,  the  other  the 
male  ; but  those  two  causes  in  general  make  only  a part  of  a whole 
animal,  or  are  rather  parts  superadded  to  an  animal.  Probably 
these  characteristics  were  first  observed  in  such  animals  as  had  the 
female  parts  complete  in  one,  and  the  male  in  the  other ; therefore 
the  terms  female  and  male  have  been  applied  to  the  whole  animal, 
dividing  them  into  two  distinct  sexes,  and  the  parts  which  formed 
the  one  sex  or  the  other  were  called  the  female  or  the  male  parts  of 
generation.  But,  upon  a more  accurate  knowledge  of  animals  and 
of  their  parts  of  generation,  these  were  found  in  many  of  the  inferior 
tribes  to  be  united  in  the  same  animal,  which  from  possessing  both 
has  got  the  name  of  hermaphrodite. 

As  the  distinction  of  male  or  female  parts  is  natural  to  most 
animals,  as  the  union  of  them  in  the  same  animal  is  also  natural  to 
many,  and  as  the  separation  of  them  is  only  a circumstance  making 
no  essential  difference  in  the  structure  of  the  parts  themselves,  it  be- 
comes no  great  effort  or  uncommon  play  in  Nature  sometimes  to 
unite  them  in  those  animals  in  which  they  are  commonly  separated  ; 
a circumstance  we  really  find  takes  place  in  many  animals  of  those 
orders  in  which  such  an  union  is  unnatural.  From  this  state  of  the 
case  hermaphrodites  may  be  divided  into  two  kinds,  the  natural  and 
unnatural. 

The  natural  hermaphrodite  belongs  to  the  inferior  and  more 
simple  genera  of  animals  of  which  there  is  a much  greater  number 
than  of  the  more  perfect ; and  as  animals  become  more  complicated, 
have  more  parts,  and  each  part  is  more  confined  to  its  particular 
use,  a separation  of  the  two  necessary  powers  for  generation  seems 
also  to  take  place.* 

that  which  is  always  called  seed  in  the  vegetable;  which  seed  is  the  part  of  such 
vegetables  in  which  the  matter  of  the  young  vegetable  exists  or  is  formed.  The 
principle  of  arrangement  in  the  farina,  or  male  part,  fitting  the  seed  for  action, 
being  at  first  not  known,  a false  analogy  between  the  vegetable  and  animal  was 
established,  and  the  matter  secreted  by  the  testes  was  called  the  seed  ; but,  from 
the  knowledge  of  the  distinct  sexes  in  the  vegetable,  it  is  well  known  that  the 
seed  is  the  female  production  in  them,  and  that  the  principle  of  arrangement  for 
action  is  from  the  male.  The  same  operation  and  principles  take  place  in  many 
orders  of  animals,  the  female  producing  a seed  in  which  is  the  matter  fitted  for 
the  first  arrangement  of  the  organs  of  the  animal,  and  which  receives  the  principle 
of  arrangement  fitting  them  for  action  from  the  male. 

[The  animals  in  which  the  organs  of  the  two  sexes  are  naturally  combined 
in  the  same  individual  are  confined  to  the  invertebrate  division,  and  are  most 
common  in  the  molluscous  and  radiate  classes.  If  the  term  hermaphrodite  may 
be  applied  to  those  species  which  propagate  without  the  concourse  of  the  sexes, 
but  in  which  no  distinct  male  organ  can  be  detected,  as  well  as  to  those  in  which 
both  male  and  female  organs  are  present  in  the  same  body,  then  there  may  be 
distinguished  three  kinds  of  hermaphroditism. 

First,  the  cryptandrous,  or  in  which  the  female  or  productive  organs  are  alone 
developed.  ' Ex.  the  accephalous  mollusks,  as  the  oyster,  lamp-cockle,  and 
ascidia;  the  cystic  entozoa,  echinoderms,  acalephes,  polyps,  and  sponges. 

Second,  the  heautandrous,  or  in  which  the  male  organs  are  developed,  but  so 
disposed  as  to  fecundate  the  ova  of  the  same  individual.  Ex.  the  cirripeds,  the 
rotifers,  the  tremaiode  and  cestoid  entozoa. 

Third,  the  allotriandrous,  or  in  which  the  male  organs  are  so  disposed  as  not  to 


72 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  unnatural  hermaphrodite,*  I believe,  now  and  then  occurs  in 
every  tribe  of  animals  having  distinct  sexes,  but  is  more  in  common 
in  some  than  in  others  ;f  and  is  to  be  met  with,  in  all  its  gradations, 

fecundate  the  ova  of  the  same  body,  butwhere  tbe  concourse  of  two  individuals  is 
required,  notwithstanding  the  co-existence  in  each  of  the  organs  of  tbe  two  sexes. 
Ex.  the  gastropodous  mollusks,  with  the  exception  of  the  pectinibranchiate  order, 
the  class  Annellida. 

All  the  otlier  invertebrates,  as  the  cephalopods  and  pectinibranchiate  gastro- 
pods, the  insects,  arachnidans  and  crustaceans,  the  epizoa,  and  the  nematoid 
entozoa,  are,  like  the  vertebrate  classes,  dioecious,  or  composed  of  male  and 
female  individuals.] 

* [The  unnatural  hermaphrodites  may  be  divided  into  those  in  which  the  parts 
peculiar  to  the  two  sexes  are  blended  together  in  different  proportions,  and  the 
whole  body  participates  of  a neutral  character,  tending  towards  the  male  and  female 
as  the  respective  organs  predominate,  and  into  those  in  which  the  male  and 
female  organs  occupy  respectively  separative  halves  of  the  body,  and  impress  on 
each  lateral  moiety  the  characteristics  of  the  sex.  This  latter  and  very  singular 
kind  of  hermaphroditism  has  hitherto  been  found  only  in  insects  and  crustaceans. 
In  the  Extracts  from  the  Minute-Book  o-f  the  Linnean  Society,  printed  in  the  14th 
Vol.  of  their  Transactions,  it  is  stated  that  Alex.  MacLeay,  Esq.,  Sec.  L.S., 
exhibited  a curious  specimen  showing  that  two  Papiliones,  referred  to  distinct 
families  by  Fabricius,  are  in  reality  the  male  and  female  of  the  same  species. 
This  specimen  presented  the  forms  and  colours  of  both  sexes,  divided  by  a longi- 
tudinal line  on  the  body:  the  right  wings  and  side  of  the  body  being  as  in  the 
male  (Papillo  Polycaon,  Fabr.),  and  the  left  as  in  the  female  {Papilio  Laodocus, 
Fabr.).  In  Loudon’s  Magazine  of  Natural  History,  (vol.  iv.  p.  434,)  an  experi- 
enced entomologist,  Mr.  J.  0.  Westwood,  has  given  descriptions  and  figures,  not 
only  of  dimidiate  hermaphrodites,  (the  example  is  the  Bombyx  Penii)  but  also  of 
quartered  hermaphrodites  : tbe  latter  singular  condition  is  exemplified  in  a speci- 
men of  the  Bombyx  castrensis,  in  which  the  right  wing,  left  antenna,  and  left  side 
of  the  abdomen  are  male;  the  left  wdng,  right  antenna,  and  right  side  of  the 
abdomen  are  female ; and  again  in  a specimen  of  the  stag-beetle  {Lucanus  Cervus), 
in  which  the  lelt  jaw  and  right  elytrum  are  masculine,  and  the  right  jaw  and  left 
elytrum  feminine.  In  most  dimidiate  hermaphrodites  the  left  side  is  masculine; 
but  an  example  of  the  contrary  has  been  observed  in  Sphinx  Populi.  It  is  to  be 
regretted  that  the  condition  of  the  internal  organs  of  generation  cannot  be  ascer- 
tained in  the  above  singular  examples  ; but  this  deficiency  is  in  some  degree 
supplied  by  the  results  of  Dr.  Nicholl’s  dissection  of  a hermaphrodite  lobster, 
(Phil.  Trans.,  xxxvi.,  p.  290,)  in  which  a testis  was  found  on  that  side  of  the 
body  which  exhibited  externally  the  male  characteristics,  and  an  ovarium  on  the 
opposite  side.] 

f Quere : Is  there  ever,  in  the  genera  of  animals  that  are  natural  hemaphrodites,  a 
separation  of  the  two  parts  forming  distinct  sexes!  If  there  is,  it  may  account 
for  the  distinction  of  sexes  ever  having  happened. a 


a [The  separation  of  the  two  sexual  organs  from  one  another  in  the  same  body 
occurs  in  many  of  that  class  of  natural  hermaphrodites  which  we  have  termed 
‘ allotriandrous ; ’ and  there  are  many  examples  in  the  Hunterian  collection 
showing  the  fact.  What,  therefore,  Mr.  Hunter  seems  here  to  refer  to  is  a spon- 
taneous fission  of  the  body  in  the  interval  separatingthe  two  sexual  parts,  so  that 
one  portion  of  the  body  shall  contain  the  male  and  the  other  the  female  organs. 
Some  annellides,  as  the  Nais,  exhibit  the  phenomenon  of  spontaneous  fission, 
but  the  separation  never  occurs  so  as  to  divide  the  two  sexual  organs  from  one 
another,  and  appropriate  one  to  each  division;  and  were  even  such  an  occurrence 
to  be  supposed  ever  to  take  place,  the  application  of  the  fact  to  explain  (he  occur- 
rence of  the  distinct  sexes  in  the  naturally  dioecious  classes  seems  more  worthy 
of  a speculatist  of  the  Lamarckian  school  than  of  a sober  observer  of  Nature.] 


OF  THE  FREE-MARTIN. 


73 


from  the  distinct  sex  to  the  most  exact  combination  of  male  and 
female  organs;  This,  I fancy,  happens  most  rarely  in  the  luiman 
species,  never  having  seen  an  instance.  I can  say  the  same  of 
dogs*  and  cats,  with  which  last,  however,  I am  less  acquainted; 
but  in  the  horse,  ass,  sheep,  and  black  cattle  it  is  very  frequent. 

There  is  one  part  common  to  both  the  male  and  female  organs 
of  generation  in  all  animals  which  have  the  sexes  distinct : in  the 
one  sex  it  is  called  the  penis,  in  the  other  the  clitoris  ; its  specific 
use  in  both  is  to  continue,  by  its  sensibility,  the  action  excited  in 
coition  till  the  paroxysm  altei’s  the  sensation.  In  the  female  it  pro- 
bably answers  no  other  purpose  ; but  in  the  male  it  is  more  com- 
plicated, to  adapt  it  for  the  purpose  of  conducting  and  expelling 
the  semen  that  has  been  secreted  in  consequence  of  the  actions  so 
excited. 

Though  the  unnatural  hermaphrodite  be  a mixture  of  both  sexes, 
and  may  possess  the  parts  peculiar  to  each  in  perfection,  yet  it 
cannot  possess  in  perfection  that  part  which  is  common  to  both. 
For  as  this  common  part  is  different  in  one  sex  from  what  it  is  in 
the  other,  and  it  is  impossible  for  one  animal  to  have  both  a penis 
and  clitoris,  the  common  part  must  of  course  partake  of  both  sexes, 
and  consequently  render  the  hermaphrodite  so  far  incomplete ; but 
these  parts  peculiar  to  each  sex  may  be  perfectly  joined  in  the 
same  animal,  which  will  convey  an  idea  of  the  truest  hermaphro- 
dite.t  Although  it  may  not  be  necessary,  to  constitute  an  herma- 
phrodite, that  the  parts  peculiar  to  the  one  sex  should  be  blended 
xvith  those  of  the  other,  in  the  same  way  that  the  penis  is  with  the 
clitoris,  yet  this  sometimes  takes  place  in  parts  whose  use  in  the 
distinct  sexes  is  somewhat  similar,  the  testicle  and  ovarium  some- 
times forming  one  body,  wdthout  the  properties  of  either.  This 
compounded  part  in  those  animals  that  have'  the  testicle  and 
ovarium  differently  situated  is  generally  found  in  the  place  allotted 
for  the  ovarium ; but  in  such  animals  as  have  the  testicle  and  ova- 
rium in  the  same  situation,  as  the  bird  tribe,  the  compound  of  the 
two,  when  it  occurs,  will  also  be  found  in  that  common  situation. 

The  parts  of  the  female  appropriated  for  the  purpose  of  supplying 
the  young  with  nourishment  are  variously  placed  in  different  ani- 
mals. In  the  horse,  black  cattle,  sheep,  and  other  graminivorous 
animals,  their  situation  is  betw'een  the  hind  legs;  and  this  being 
also  the  place  allotted  for  the  testicles  of  the  male  of  this  tribe,  and 
probably  of  all  those  in  w'hich  the  testicles  come  out  of  the  cavity 
of  the  belly;  in  the  hermaphrodite  therefore,  wdfich  has  both  these 

* [For  an  example  of  hermaphroditism  in  a door,  see  Phil.  Trans.,  Ixxxix.  p.  157.] 
[In  a recent  work  on  hermaphroditism,  by  Geoffroy  St.  Hilaire,  a mechanical 
reason  is  assigned  for  the  non-existence  of  a penis  and  clitoris  in  the  same  indi- 
vidual, viz.,  because  both  parts  arise  from  the  same  points  of  the  pelvis:  but  in 
many  animals  neither  the  one  nor  the  other  has  any  bony  attachment,  and  the 
explanation  above  given,  founded  on  the  similarity  of  their  functions,  is  more 
philosophical  and  satisfactory.] 


8 


74 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


parts,  the  testicles  must  to  a certain  degree  descend  into  the  udder, 
though  that  cannot  receive  them  so  readily  as  the  scrotum. 

The  hermaphrodites  which  I have  seen  have  always  appeared 
externally  and  at  first  view  to  be  females,  from  the  penis  being  the 
part  principally  deficient,  and  there  being  an  opening  behind  like 
the  bearing  in  the  female ; and  as  the  testicles  in  such  hermaphro- 
dites seldom  come  down,  the  udder  is  left  to  occupy  its  proper 
place.  In  animals  the  female  of  which  is  preserved  for  breeding 
only,  as  sheep,  goats,  pigs,  &c.,  these  are  generally  kept,  from  their 
being  supposed  to  be  females. 

Among  horses  such  hermaphrodites  are  very  frequent : I have 
seen  several,  but  never  dissected  any.  The  most  complete  was  one 
in  which  the  testicles  had  come  down  out  of  the  abdomen  into  the 
place  where  the  udder  should  have  been  (viz.,  more  forward  than 
the  scrotum),  and,  though  not  so  pendulous  as  the  scrotum  in  the 
perfect  male  of  such  animals,  had  all  the  appearance  of  an  udder. 
There  were  also  two  distinct  nipples,  which,  although  they  exist  in 
the  male,  have  no  perfect  form,  being  blended  with  the  sheath  or 
prepuce,  of  which  there  was  none  here.  The  external  female  parts 
were  exactly  similar  to  those  of  the  perfect  female;  but  instead  of 
a common-sized  clitoris,  there  was  one  about  five  or  six  inches  long, 
M’hich  when  erect  pointed  almost  directly  backwards. 

I procured  a foal-ass,  very  similar  in  external  appearance  to  the 
horse  above-mentioned,  and  killed  it  to  examine  the  parts.  It  had 
two  nipples,  but  the  testicles  were  not  come  down  as  in  the  above, 
owing  perhaps  to  the  animal’s  being  yet  too  young.  There  was 
no  penis  passing  round  the  pubis  to  the  belly,  as  in  the  perfect  male 
ass. 

The  external  female  parts  were  similar  to  those  of  the  she-ass. 
Within  the  entrance  of  the  vagina  was  placed  the  clitoris  ; but  much 
longer  than  that  of  a true  female,  it  measuring  about  five  inches. 
The  vagina  was  pervious  a little  beyond  the  opening  of  the  urethra 
into  it,  and  from  thence  up  to  the  fundus  of  the  uterus  there  W'as  no 
canal.  The  uterus  was  hollow  at  the  fundus,  or  had  a cavity  in  it, 
and  then  divided  into  two  horns,  which  were  also  pervious.  Beyond 
the  termination  of  the  two  horns  were  placed  the  ovaria  as  in  the 
true  female;  but  I could  not  find  the  Fallopian  tubes.  From  the 
broad  ligaments,  to  the  edges  of  which  the  horns  of  the  uterus  and 
ovaria  are  attached,  there  passed  towards  each  groin  a part  similar 
to  the  round  ligaments  in  the  female,  which  were  continued  into 
the  rings  of  the  abdominal  muscles;  but  with  this  difiefence,  that 
there  accompanied  them  a process  or  theca  of  the  peritoneum,  simi- 
lar to  the  tunica  vaginalis  communis  in  the  male  ass;  and  in  these 
thecm  were  found  the  testicles,  but  I could  not  observe  any  vasa 
deferentia  passing  from  them. 

Here  then  w'ere  found,  in  the  same  animal,  the  parts  peculiar  to 
each  sex  (although  very  imperfect),  and  that  part  which  is  common 
to  both,  but  different  in  each,  was  a kind  of  medium  of  that 
difference. 


OF  THE  FREE-MARTIN, 


75 


Something  similar  to  the  above  I have  seen  in  sheep,  goats,  &c.; 
but  I shall  not  at  present  trouble  the  reader  with  a description  of 
hermaphrodites  in  general,  as  it  is  a very  extensive  subject,  admit- 
ting of  great  variety,  which  would  make  them  appear  a production 
of  chance ; whereas  the  intention  of  this  account  is  to  point  out  a 
circumstance  which  takes  place  in  the  production  of  hermaphro- 
dites in  black  cattle  that  appears  to  be  almost  an  established  prin- 
ciple in  their  propagation,  and  is  perhaps  peculiar  to  that  species 
of  animal. 

It  is  a fact  known,  and  I believe  almost  universally  understood, 
that  when  a cow  brings  forth  two  calves,  and  one  of  them  a bull- 
calf  and  the  other  to  appearance  a cow,  that  the  cow-calf  is  unfit 
for  propagation,  but  the  bull-calf  grows  up  into  a very  proper  bull. 
Such  a cow-calf  is  called  in  this  country  a free-martin,  and  is 
commonly  as  well  known  among  the  farmers  as  either  cow  or  bull. 
Although  it  will  appear,  from  the  description  of  this  animal,  that  it 
is  an  hermaphrodite  (being  in  no  respect  different  from  other  herma- 
phrodites), yet  I shall  retain  the  term,  free-martin,  to  distinguish  the 
hermaphrodite  produced  in  this  way  from  those  which  resemble  the 
hermaphrodite  of  other  animals  ; for  1 know  that  in  black  cattle 
such  a deviation  may  be  produced  without  the  circumstance  of 
twins  ; and  even  where  there  are  twins,  the  one  male  the  other  a 
female,  they  may  both  have  the  organs  of  generation  perfectly 
formed.  But  when  I speak  of  those  which  are  not  twins,  I shall 
call  them  hermaphrodites  : the  only  circumstance  worth  our  notice 
being  a singularity  in  the  mode  of  production  of  the  free-martin, 
and  its  being,  as  for  as  I yet  know,  peculiar  to  black  cattle. 

This  calf  has  all  the  external  marks  of  a cow-calf,  similar  to 
what  was  mentioned  in  the  unnatural  hermaphrodite,  viz.,  the  teats 
and  the  external  female  parts  called  by  farmers  the  bearing;  and 
when  they  are  preserved  by  those  who  know  the  above  fact,  it  is 
not  fur  propagation,  but  for  all  the  purposes  of  an  ox  or  spayed 
heifer,  viz.,  to  yoke  with  the  oxen  and  to  fatten  for  the  table.* 

It  is  known  that  they  do  not  breed ; they  do  not  show  the  least 
inclination  of  the  bull,  nor  does  the  bull  ever  take  the  least  notice 
of  them.f  They  very  much  resemble,  in  form,  the  ox  or  spayed 
heifer,  being  considerably  larger  than  either  the  bull  or  the  cow, 
having  the  horns  very  similar  to  the  horns  of  an  ox. 

The  bellow  of  the  free-martin  is  similar  to  that  of  an  ox,  having 
more  resemblance  to  that  of  the  cow  than  of  the  bull.  Free-mar- 
tins  are  very  much  disposed  to  grow  fat  with  good  food.  The 
flesh,  like  that  of  the  ox  or  spayed  heifer,  is  generally  much  finer 
in  the  fibre  than  either  the  bull  or  cow,  is  supposed  to  exceed  that 
of  the  ox  and  heifer  in  delicacy  of  flavour,  and  bears  a higher  price 
at  market. 

* I need  hardly  observe  here,  that  if  a cow  has  twins,  and  they  are  both  bull- 
calves,  that  they  are  in  every  respect  perfect  bulls ; or  if  they  are  both  cow-calves, 
they  are  perfect  cows. 

f Vide  Leslie  on  Husbandry,  pp.  98,  99. 


76 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


However,  it  seems  that  this  is  not  universal,  for  I was  lately 
informed  by  Charles  Palmer,  Esq.,  of  Luckley  in  Berkshire,  that  a 
free-martin  having  been  killed  in  his  neighbourhood,  from  the 
general  idea  of  its  being  better  meat  than  common,  every  neigh- 
bour bespoke  a piece,  which  turned  out  nearly  as  bad  as  bull-beef; 
worse,  at  least,  than  that  of  a cow.  It  is  probable  that  circum- 
stance might  arise  from  this  animal  having  more  the  properties  of 
a bull  than  the  cow,  as  we  shall  see  hereafter  that  they  are  some- 
times more  the  one  than  the  other.^ 

Although  what  I have  advanced  with  respect  to  the  production 
of  free-martins  be  in  general  true,  yet,  by  the  assistance  of  Benja- 
min Way,  Esq.,  of  Denham,  near  Uxbridge,  who  knew  my  anxiety 
to  ascertain  this  point,  I was  lately  furnished  with  an  instance 
W'hich  proves  that  it  does  not  invariably  hold  good. 

One  of  his  cows  having  produced  twins,  which  w'ere  to  appear- 
ance male  and  female,  upon  a supposition  that  the  cow-calf  w'as  a 
free-martin,  he  obligingly  offered  either  to  give  it  me,  or  to  keep  it 
till  it  grew  up,  that  we  might  determine  the  fact  : as  I conceived  it 
to  be  a free-martin,  and  was  to  have  the  liberty  of,  examining  it  after 
death,  I desired  that  he  would  keep  it ; but,  unfortunately,  it  died  at 
about  a month  old.  Upon  examining  the  organs  of  generation, 
they  appeared  to  be  those  of  the  female,  and  perfectly  formed  ; but 
to  make  this  more  certain,  I procured  those  of  acomimon  cow-calf, 
and  comparing  them  together,  found  them  exactly  alike.  This 
made  us  regret  that  the  animal  had  not  lived  to  an  age  that  might 
have  determined  if  it  was  capable  of  breeding  ; for  the  construction 
of  the  parts  being  to  appearance  perfect,  is  not  sufficient  of  itself  to 
stamp  it  a true  or  perfect  female:  as  I can  suppose  that  the  parts 
being  perfectly  formed,  but  without  the  power  of  propagation,  may 
constitute  the  most  simple  kind  of  hermaphrodite.  It  is,  however, 
most  probable  that  this  was  a perfect  female,  which  is  an  excep- 
tion to  the  common  rule  ; and  I have  been  informed  there  are 
instances  of  such  twins  breeding.']'  If  there  are  such  deviations,  aS 
of  twins  being  perfect  male  and  female,  why  should  there  not  be, 
on  the  other  hand,  an  hermaphrodite  produced  singly,  as  in  other 
animals  1 I had  the  examination  of  one  which  seemed,  upon  the 

* The  Romans  called  the  bull,  taunis;  tliey,  however,  talked  of  tauroe  in  the 
feminine  gender.  And  Stephen  observes,  that  it  was  thought  the  Romans  meant 
by  taurae,  barren  cows,  and  called  them  by  this  name  because  they  did  not  con- 
ceive. He  also  (juotes  a passage  from  Columella,  lib.  vi.  cap.  22,  “and  like  the 
turoe,  which  occupy  the  place  of  fertile  cows,  should  be  rejected,  or  sent  away.” 
He  likewise  quotes  Varro,  De  Re  Rustica,  lib.  ii.  cap.  5,  “ The  cow  which  is 
barren  is  called  taura.”  From  which  we  may  reasonably  conjecture  that  the 
Romans  had  not  the  idea  of  the  circumstances  of  their  production. 

I [An  instance  of  this  nature  is  recorded  in  the  fifth  volume  of  Loudon’s 
Magazine  of  Natural  History,  p.  765.  “Jos.  Holroyd,  Esq.,  of  Withers,  near 
Leeds,  had  a cow  which  calved  twins,  a bull-calf  and  a cow-calf.  As  popular 
opinion  was  against  the  cow-calf  breeding,  it  had  been  considered  a free-martin, 
Mr.  Holroyd  was  determined  to  make  an  experiment  of  them,  and  reared  them 
together.  They  copulated,  and  in  due  time  the  heifer  brought  forth  a bull-calf, 
and  she  regularly  had  calves  for  six  or  seven  years  afterwards.”] 


OF  THE  FREE-MARTIN. 


77 


strictest  inquiry, .to  have  been  a single  calf;  and  T am  the  more 
inclined  to  think  this  true,  from  having  found  a number  of  her- 
maphrodites among  black  cattle,  without  the  circumstances  of  their 
birth  being  ascertained. 

Hermaphrodites  are  to  be  met  with  in  sheep ; but,  from  the 
account  given  of  them,  I should  suppose  that  they  are  not  free- 
martins.  I have  seen  several  which  were  supposed  to  be  her- 
maphrodites, but  which  were  imperfect  males,  having  the  penis 
terminating  in  the  perinasum,  the  orifice  of  which  appeared  like  the 
bearing  in  the  female.  Such  are  not  naturally  stimulated  to  put 
themselves  in  the  position  of  the  female  when  they  void  their  urine, 
so  that  when  it  passes  the  surrounding  parts  are  wetted  by  it,  and 
being  covered  with  wool,  and  retaining  the  urine,  keeps  them  con- 
tinually moist,  and  gives  the  animal  a strong  smell.  They  are 
mentioned  as  both  male  and  female. 

I believe  it  had  never  been  even  conjectured,  notwithstanding  all 
these  peculiarities,  what  was  the  true  nature  of  the  free-martin 
and  from  the  singularity  of  the  animal,  and  the  account  of  its 
production,  I was  almost  tempted  to  suppose  the  whole  a vulgar 
error.  Yet  by  the  universality  of  the  testimony  in  its  favour,  it  ap- 
pearing to  have  some  foundation,  I eagerly  sought  for  an  oppor- 
tunity to  see  and  examine  them.  I have  succeeded  in  this  inquiry, 
and  have  seen  several,  the  first  ofwhich  was  one  belonging  to  John 
Arbuthnot,  Esq.,  of  Mitcham,  and  was  calved  in  his  own  farm.  He 
was  so  obliging  as  to  allow  me  to  satisfy  myself,  first  by  permitting 
a drawing  to  be  made  of  the  animat  while  alive,  which  was  executed 
by  Mr.  Gilpin,  and  afterwards  to  examine  the  parts  when,  the  animal 
died.  At  the  time  the  drawing  was  made  of  Mr.  Arbuthnot’s  free- 
rnartin,  John  Wells,  Esq.,  of  Bickley  Farm,  near  Bromley  in  Kent, 
was  present,  and  informed  us  that  a cow  of  his  had  calved  two 
calves,  one  of  which  was  a bull-calf,  and  the  other  a cow-calf.  I 
desired  Mr.  Arbuthnot  to  request  Mr.  Wells  to  keep  them,  or  let  me 
buy  them  of  him  ; but  from  his  great  desire  of  natural  knowledge, 
he  very  readily  consented  to  preserve  both  till  the  bull  showed  all 
the  signs  of  a good  bull ; and  when  the  free-martin  was  killed,  he 
allowed  me  to  inspect  the  parts. 

Of  all  the  specimens  which  I have  dissected,  I shall  only  give 
the  descriptions  of  the  three  which  point  out  most  distinctly  the 
complete  free-martin  with  the  gradations  towards  the  male  and 
female. 


THE  DESCRIPTION  OF  THE  THREE  FREE-MARTINS. 

Mr.  Wright's  Free-Martin,  five  years  old. 

This  animal  had  more  the  appearance  and  general  character  of 
the  ox,  or  spayed  heifer,  than  of  either  the  bull  or  cow.  The 
vagina  terminated  in  a blind  end,  a little  way  beyond  the  opening 

8* 


78 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


of  the  urethra,  from  which  the  vagina  and  uterus.were  impervious. 
The  uterus,  at  its  extreme  part,  divided  into  two  horns.  At  the 
termination  of  the  horns  were  placed  the  testicles,  instead  of  the 
ovaria,  as  is  the  case  in  the  female.  The  reasons  why  I call  these 
bodies  testicles,  are  the  following.  First,  they  were  above  twenty 
times  larger  than  the  ovaria  of  the  cow,  and  nearly  the  size  of  the 
testicles  of  the  bull,  or  rather  of  those  of  the  ridgil,  the  bull  whose 
testicles  never  come  down.  Secondly,  the  spermatic  arteries  were 
similar  to  those  of  the  bull,  especially  of  the  ridgil.  Thirdly,  the 
cremaster  muscle  passed  up  from  the  rings  of  the  abdominal  muscles 
to  the  testicles,  as  it  does  in  the  ridgil.* 

There  were  the  two  bags  placed  behind,  between  the  bladder  and 
the  uterus.  Their  ducts  opened  into  the  vagina,  a very  little  way 
beyond  the  opening  of  the  urethra ; but  there  was  nothing  similar 
to  the  vasa  deferentia. 

As  the  external  parts  had  more  of  the  cow  than  the  bull,  the 
clitoris,  which  may  be  reckoned  an  external  part,  was  also  similar 
to  that  of  the  cow,  not  at  all  in  a middle  state,  between  the  penis  of 
the  hull  and  the  clitoris  of  the  cow,  as  I have  described  in  the  her- 
maphrodite horse.  There  were  four  teats:  the  glandular  part  of 
the  udder  was  but  small. 

This  animal  cannot  be  said  to  have  been  a mixture  of  all  the 
parts  of  both  sexes,  for  the  clitoris  had  nothing  similar  to  the  penis  in 
the  male,  and  it  was  deficient  in  the  female  parts,  by  having  nothing 
similar  to  the  ovaria ; neither  had  the  uterus  a cavity. 

Mr.  JirhidhnoL'’ s Free-Martin.'\ 

The  external  parts  were  rather  smaller  than  in  the  cow.  The 
vagina  passed  on,  as  in  the  cow,  to  the  opening  of  the  urethra,  and 
then  it  began  to  contract  into  a small  canal,  which  passed  on  to  the 
division  of  the  uterus  into  the  two  horns,  each  horn  passing  along 
the  edge  of  the  broad  ligament  laterally  towards  the  ovaria. 

At  the  termination  of  these  horns  were  placed  both  the  ovaria 
and  the  testicles  ; they  were  nearly  of  the  same  size,  and  about  as 
large  as  a small  nutmeg. 

To  the  ovariaj  I could  not  find  any  Fallopian  tube. 

To  the  testicles  were  vasa  deferentia,  but  they  were  imperfect. 
The  left  one  did  not  reach  near  to  the  testicle  ; the  right  only  came 

* Although  I call  these  bodies  testicles,  for  the  reason  given,  yet  they  were 
only  imitations  of  them,  for  when  cut  into  they  had  nothing  of  the  structure  of 
the  testicle;  not  being  similar  to  anything  in  Nature,  they  had  more  the  appear- 
ance of  disease.  From  the  seeming  imperfection  of  the  animal  itself,  it  was  not 
to  be  supposed  that  they  should  be  testicles ; for  then  the  animal  should  have 
partaken  of  the  bull,  which  it  certainly  did  not. 

I This  animal  was  seven  years  old  ; had  been  often  yoked  with  the  oxen;  at 
other  times  went  with  the  cows  and  bull ; but  never  showed  any  desires  for 
either  the  one  or  the  other.  ' 

p [It  is  probable  that  these  bodies  were,  as  in  the  case  previously  noted,  re- 
mains of  the  corpora  Wolffiana.] 


OF  AN  EXTRAORDINARY  PHEASANT. 


79 


close  to  it,  but  did  not  terminate  in  a body  called  the  epididymis. 
They  were  both  pervious,  and  opened  into  the  vagina  near  the 
opening  of  the  urethra. 

On  the  posterior  surface  of  the  bladder,  or  betvveen  the  uterus  and 
bladder,  were  the  two  bags,  called  vesiculas  seminales  in  the  male, 
but  much  smaller  than  what  they  are  in  the  bull ; the  ducts  opened 
along  with  the  vasa  deferentia.  This  was  more  entitled  to  the 
name  of  hermaphrodite  than  the  first  or  third,  for  it  had  a mixture 
of  all  the  parts,  though  all  were  imperfect. 

Mr.  Wells’s  Free-Mai'tin. 

This  animal  was  between  three  and  four  years  old  when  killed ; 
and  had  never  been  observed  to  show  any  signs  of  desire  for  the 
male,  although  it  went  constantly  with  one ; and  looked  more  like 
a heifer  than  free-martins  usually  do. 

The  teats  and  udder  were  small  compared  with  those  of  a heifer, 
but  rather  larger  than  in  either  of  the  former  examples;  the  begin- 
ning of  the  vagina  was  similar  to  that  of  the  cow,  but  soon  ter- 
minated a little  beyond  the  opening  of  the  urethra,  as  in  the  first- 
described.  The  vagina  and  uterus,  to  external  appehrance,  were 
continued,  although  not  pervious,  and  the  uterine  part  divided  into 
two  horns,  at  the  end  of  which  were  the  ovaria. 

I could  not  observe  in  this  animal  any  other  body  which  I could 
suppose  to  be  the  testicle. 

There  was  on  the  side  of  the  uterus  an  interrupted  vas  deferens 
broken  off  in  several  places. 

Behind  the  bladder,  or  between  that  and  the  vagina,  were  the 
bags  called  vesiculse  seminales,  betw'een  which  were  the  termina- 
tions of  the  two  vasa  deferentia. 

The  ducts  of  the  bags,  and  the  vasa  deferentia,  opened  as  in  the 
last  instance. 

This  could  not  be  called  an  exact  mixture  of  all  the  parts  of  both 
sexes,  for  here  was  no  appearance  of  testicles. 

The  female  parts  were  imperfect,  and  there  was  the  addition 
of  part  of  the  vasa  deferentia,  and  the  bags  called  vesiculse 
seminales. 

This  circumstance  of  having  no  testicles,  perhaps,  W'as  the 
reason  why  it  had  more  the  external  appearance  of  a heifer  than 
what  they  commonly  have,  and  more  than  either  of  the  two 
former. 


4.  AN  ACCOUNT  OF  AN  EXTRAORDINARY  PHEASANT. 

Every  deviation  from  that  original  form  and  structure  which 
gives  the  distinguishing  character  to  the  productions  of  Nature, 
may  not  improperly  be  called  monstrous.  According  to  this 


80 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


acceptation  of  the  term,  the  variety  of  monsters  will  be  almost 
infinite;*  and,  as  far  as  my  knowledge  has  extended,  there  is  not 
a species  of  animal,  nay,  there  is  not  a single  part  of  an  animal 
body,  which  is  not  subject  to  an  extraordinary  formation. 

Neither  does  this  appear  to  be  a matter  of  mere  chance;  for  it 
may  be  observed  that  every  species  has  a disposition  to  deviate  from 
Nature  in  a manner  peculiar  to  itself.f  It  is  likewise  worthy  of 
ren)ark,  that  each  species  of  animals  is  disposed  to  have  nearly  the 
same  sort  of  defects,  and  to  have  certain  supernumerary  parts  of 
the  same  kind:  yet  every  part  is  not  alike  disposed  to  take  on  a 

* [Mr.  Hunter  attempted,  notwithstanding,  to  reduce  this  variety  of  monsters 
to  definite  groups,  and  left  the  following  outline  of  a classification  of  monsters, 
in  an  explanatory  introduction  to  the  extensive  series  of  those  objects  in  his 
collection  : 

“ 1.  Monsters  from  preternatural  situation  of  parts, 

“ 2, addition  of  parts. 

“ 3. deficiency  of  parts. 

“ 4, combined  addition  and  deficiency  of  parts,  as  in  herma- 

phroditical  malformation.” 

Licetus,'!  Huber,'!  and  Malacarne'  had  proposed  classifications  of  monsters 
prior  to  the  time  of  Hunter,  all  of  which  are  more  or  less  tinctured  with  the 
superstitions  of  the  times;  thus,  the  tenth  class  in  the  system  of  Licetus  is  appro- 
priated to  the  ofifspring  of  the  illicit  intercourse  of  demons  with  women:  the 
fifteenth  of  Malacarne  contains  the  brutes  with  human  members,  &c.  Blumen- 
bach,  tow’ards  the  end  of  the  eighteenth  century,  published  an  arrangement  of 
monsters  which  closely  resembles  that  of  Hunter;  he,  however,  distinguishes, 
but  without  sufficient  reason,  unnatural  hermaphrodites  from  monsters,  and 
divides  the  latter  into 

“ 1.  Monsters  by  an  unnatural  conformation  of  certain  parts  of  the  body, — 
Fabrica  aliena. 

“ 2. transposition  of  parts, — S'dus  mutatus. 

“ 3. a deficiency  of  parts, — Monstra per  defectum. 

“ 4. supernumerary  parts, — Monstra  per  excessum." 

The  study  of  the  various  congenital  aberrations  from  the  specific  form  presented 
in  the  different  classes  of  the  animal  kingdom,  has  since  been  ably  and  success- 
fully pursued  by  Meckel,  Geoffrey  St.  Hilaire,  Otto,  Breschet,  Charuet,  &c,,  the 
general  results  of  whose  labours  may  be  found  in  the  Histoire  Generate  et  Particu- 
lierc  des  Anomalies  de  V Organization  chez  I' Homme  et  les  Animaux,  ou  F'raite  de 
Teratohgie,  by  Isid.  Geoffroy  Saint-Hilaire : 8vo,  1832.] 

f [The  value  of  the  principle  here  enunciated  will  be  appreciated,  when  it  is 
stated  that  it  is  the  basis  of  the  latest  and  most  elaborate  work  on  the  subject  of 
monsters.  It  is  claimed  for  Geoffroy  St.  Hilaire  as  the  most  important  of  his 
deductions  in  Teratology,  and  the  chief  point  in  which  his  system  differs  from, 
and  is  superior  to,  those  of  his  predecessors.  “ C’est  de  principes  precisement 
inverses  que  mon  pere  a pris  sur  point  de  depart;  et  c’est  aussi,  comme  cela 
devait  etre  a des  resultats  inverses  qu’il  est  parvenu.  Etablissant,  par  un  grand 
nombre  de  recherches,  que  les  monstres  sont,  comme  les  etres  dits  normaux, 
soumis  a des  regies  constantes,  il  est  conduit  a admettre  que  la  metbode  de  classi- 
fication que  les  naturalistes  emploient  pour  les  seconds,  pent  etre  appliquee  avec 
succes  aux  premiers.”  Isid.  Geoffroy  St.-Hilaire,  loc.  cit.,  p.  99.] 


> Fortunius  Licetus,  De  Monsiris,  ex  reccnsione  G.  Blasii : Amstelodami,  1665, 
4to. 

>>  Ohservationes  nonnullse  de  Monstns : 4to.  Cassel,  1748. 

c 41  p)e’  Mostri  umani  de’  Caretteri  fondamentali  su  cui  ne  se  portrebbe  stabilire 
la  Classificazione,”  Mem.  della  Soc.  Ital.,  tom.  ix.  4. 


OF  AN  EXTRAORDINARY  PHEASANT. 


SI 


great  variety  of  forms ; but  each  part  of  each  species  seems  to  have 
its  monstrous  form  originally  impressed  upon  it.* 

It  is  well  known  that  many  orders  of  animals  have  the  two  parts 
designed  for  the  purpose  of  generation  different  in  individuals  of 
the  same  species,  by  which  they  are  distinguished  into  male  and 
female;  but  this  is  not  the  only  mark  of  distinction,  in  the  greatest 
part  the  male  being  distinguished  from  the  female  by  various  other 
marks.  The  varieties  which  are  found  in  the  parts  of  generation 
themselves  I shall  call  the  first  or  principal  marks,  being  originally 
formed  in  them,  and  belonging  equally  to  both  sexes;  all  others 
depending  upon  these  I shall  call  secondary,  as  not  taking  place  till 
the  first  are  becoming  of  use,  and  being  principally,  although  not 
entirely,  in  the  male. 

One  of  the  most  general  marks  is,  the  superior  strength  of  make 
in  the  male  ; and  another  circumstance,  perhaps  equally  so,  is  this 
strength  being  directed  to  one  part  more  than  another,  which  part 
is  that  most  immediately  employed  in  fighting.  This  difference  in 
external  form  is  more  particularly  remarkable  in  the  animals  whose 
females  are  of  a peace-able  nature,  as  are  the  greatest  number  of 
those  which  feed  on  vegetables,  and  the  marks  to  discriminate  the 
sexes  are  in  them  very  numerous.  The  males  of  almost  every  class 
of  animals  are  probably  disposed  to  fight,  being,  as  I have  observed, 
stronger  than  the  females;  and  in  many  of  these  there  are  parts 
destined  solely  for  that  purpose,  as  the  spurs  in  the  cock,  and  the 
horns  in  the  bull ; and  on  that  account  the  strength  of  the  bull  lies 
principally  in  his  neck  ; that  of  the  cock  in  his  limbs. 

In  carnivorous  animals,  whose  prey  is  often  of  a kind  which 
requires  strength  to  kill,  we  do  not  find  such  a difference  in  the 
form  of  the  male  and  female,  very  little  being  discernible  in  the  dog 
and  bitch,  in  the  he  or  she  cat,  or  in  the  cock  and  hen  of  the  eagle.f 
A difference,  however,  is  often  perceivable  in  the  whole  or  in  some 
part  of  their  external  covering  ; the  mane  of  the  lion  distinguishing 
him  from  the  lioness  ; and  the  males  of  such  animals  as  neither  fight 
nor  feed  on  flesh,  being  only  distinguishable  from  the  female  by 
some  peculiarity  in  the  covering  of  their  bodies,  as  the  cock  and 
hen  in  many  birds.  The  male  of  the  human  species  is  distinguished 

* [In  this  principle  Mr.  Hunter  is  opposed  to  Geoffroy  St. -Hilaire,  who  attri- 
buted the  production  Q'ordonnee)  of  monstrosities  to  the  operation  of  exterior  or 
mechanical  causes  at  some  period  of  fcetal  development.  Defective  formation  in 
parts  of  a foetus  has  indeed  been  produced  by  destroying  a portion  of  the  re.«pira- 
tory  surface  of  an  egg  during  incubation ; but  this  result  by  no  means  affords 
adequate  grounds  for  assigning  as  the  sole  cause  of  every  malformation  accidental 
adhesions  between  the  foetus  and  its  coverings.  Mr.  Hunter  also  made  experi- 
ments with  reference  to  monstrosities,  and  succeeded  in  effecting  wliat,  at  first 
sight,  seems  the  most  difficult  to  produce,  viz.,  the  monsters  by  excess,  of  w^iich 
several  specimens  of  Lacerta,  with  a double  tail  (No.  2219 — 2223),  afford  exam- 
ples. It  is  evident,  however,  fro-m  the  expression  in  the  concluding  paragraph 
of  the  text,  that  he  regarded  the  cause  of  congenital  malformation  as  existing  in 
the  primordial  germ.] 

I [The  difference  in  the  size  of  the  two  sexes  is  sufficiently  marked  in  most  of 
the  Raptorial  birds  ; but  it  is  the  female  which  has  the  advantage  in  this  respect.] 


82 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


from  the  female  both  by  his  general  strength  and  his  covering,  as 
also  by  a difference  of  voice. 

In  these  orders  of  animals  whose  sexes  are  distinct,  we  may  not 
only  observe  the  genital  organs  to  be  subject  to  mal-conformation, 
as  in  any  other  part  of  the  animal,  but  that  an  attempt  is  sometimes 
made  to  unite  the  two  organs  in  the  same  animal  body,  making 
what  may  be  called  an  unnatural  hermaphrodite.  In  producing 
the  unnatural  hermaphrodite  the  same  laws  seem  to  operate  as  in 
the  mal-conformation  of  other  parts  of  animals  ; it  being  observable, 
that  these  deviations  obtain  through  a whole  species  precisely  in  the 
same  manner.  I have  already  given  an  account  of  the  free-martin, 
which  exhibits  a mixture  of  the  two  parts  of  generation  in  the 
same  animal. 

It  is  my  intention  at  present  to  extend  my  inquiry  on  this  subject 
no  further  than  what  relates  to  the  resemblance  which  one  sex  bears 
to  another  in  those  distinguishing  properties  which  I term  secondary; 
for  w'e  find  that  thei’e  is  often  a change  of  the  natural  properties  of 
the  female  sex  into  those  of  the  secondary  of  the  male  ; the  female, 
in  such  cases,  now  and  then  assuming  the  secondary  peculiarities 
of  the  male.  It  is  to  be  observed,  that  some  classes  are  more  liable 
than  others  to  this  change,  a singular  example  of  which  is  to  be  the 
subject  of  the  following  pages. 

To  bring  the  foregoing  observations  into  one  point  of  view,  I 
here  beg  leave  to  remark,  that  in  animals  just  born,  or  very  young, 
there  are  no  peculiarities  to  distinguish  one  sex  from  the  other,  ex- 
clusive of  what  relates  to  the  organs  of  generation,  which  can  only 
be  in  those  who  have  external  parts  ; and  that  towards  the  age  of 
maturity  the  discriminating  changes  before  mentioned  begin  to 
appear  ; the  male  then  losing  that  resemblance  he  had  to  the  female 
in  various  secondary  properties  ;*  but  that  in  all  animals  which  are 
not  of  any  distinct  sex,  called  hermaphrodites,  there  is  no  such 
alteration  taking  place  in  their  form  when  they  arrive  at  that  age. 
It  is  evidently  the  male  which  at  this  time  in  such  respects  recedes 
from  the  female,  every  female  being  at  the  age  of  maturity  more 
like  the  young  of  the  same  species  than  the  male  is  observed  to  be; 
and  if  the  male  is  deprived  of  his  testes  when  young,  he  retains 
more  of  the  original  youthful  form,  and  therefore  more  resembles 
the  female. 

From  hence  it  might  be  supposed  that  the  female  character  con- 
tains more  truly  the  specific  properties  of  the  animal  than  the  male ; 
but  the  character  of  every  animal  is  that  w'hich  is  marked  by  the 
properties  common  to  both  sexes,  which  are  found  in  a natural 
hermaphrodite,  as  in  a snail,  or  in  animals  of  neither  sex,  as  the 
castrated  male  or  spayed  female. 

But  where  the  sexes  are  separate,  and  the  animals  have  two 

* This  is  not  common  to  all  animals  of  distinct  sexes,  for  in  fishes  there  is  no 
great  difference  ; nor  in  many  insects  ; nor  in  dogs,  as  has  been  already  observed  : 
however,  it  is  considerable  in  many  quadrupeds,  but  appears  to  be  most  so  in 
birds. 


OF  AN  EXTRAORDINARY  PHEASANT. 


83 


characters,  the  one  cannot  more  than  the  other  be  called  the  true, 
as  the  real  distinguishing  marks  of  each  particular  species,  as  has 
been  mentioned  above,  are  those  common  to  both  sexes,  and  which 
are  likewise  in  the  unnatural  hermaphrodite.  That  these  properties 
give  the  distinct  character  of  such  animals  is  evident,  for  the  cas- 
trated male  and  the  spayed  female  have  both  the  same  common 
properties ; and  when  I treated  of  the  free-martin,  which  is  a 
monstrous  hermaphrodite,  I observed  that  it  was  more  like  the 
ox  than  the  cow  or  bull;  so  that  the  marks  characteristic  of  the 
species  which  are  found  in  the  animal  of  a double  sex  are 
imitated  by  depriving  the  individual  of  certain  sexual  parts,  in 
consequence  of  which  it  retains  only  the  true  properties  of  the 
species. 

They  are  curious  facts  in  the  natural  history  of  animals,  that  by 
depriving  either  sex  of  the  true  parts  of  generation,  they  shall  seem 
to  approach  each  other  in  appearances,  and  acquire  a resemblance 
to  the  unnatural  hermaphrodite. 

In  some  species  of  animals  that  have  the  secondary  properties  we 
have  mentioned,  there  is  a deviation  from  the  general  rules,  by  the 
perfect  female,  with  respect  to  the  parts  of  generation,  assuming 
more  or  less  the  secondary  character  of  the  male. 

This  change  does  not  appear  to  arise  from  any  action  produced 
at  the  first  formation  of  the  animal,  and  in  this  respect  is  similar  to 
what  takes  place  in  the  male ; neither  does  it  grow  up  with  the 
animal  as  it  does  to  a certain  degree  in  the  male,  but  seems  to  be 
one  of  those  changes  which  happen  at  a particular  period,  similar 
to  many  common  and  natural  phenomena:  like  to  what  is  ob- 
served of  the  horns  of  the  stag,  which  differ  at  different  ages; 
or  to  the  mane  of  the  lion,  which  does  not  grow  till  after  his  fifth 
year,  &c.* 

This  change  has  been  observed  in  some  of  the  bird  tribe,  but 
principally  in  the  common  pheasant ; and  it  has  been  observed  by 
those  who  are  conversant  with  this  bird,  when  wild,  that  there 
every  now  and  then  appears  a hen  pheasant  with  the  feathers  of  a 
cock:  all,  however,  that  they  have  described  on  the  subject  is,  that 
this  animal  does  not  breed,  and  that  its  spurs  do  not  grow.  Some 
years  ago  one  of  these  was  sent  to  the  late  Dr.  William  Hunter, 
which  I examined,  and  found  it  to  have  all  the  parts  peculiar  to  the 
female  of  that  bird.  This  specimen  is  still  preserved  in  Dr.  Hun- 
ter’s museum. 

Dr.  Pitcairn  having  received  a pheasant  of  this  kind  from  Sir 
Thomas  Harris,  showed  it  as  a curiosity  to  Sir  Joseph  Banks 
and  Dr.  Solander.  I happening  to  be  then  present,  was  desired 
to  examine  the  bird,  and  the  following  was  the  result  of  my 
examination. 

I found  the  parts  of  generation  to  be  truly  female,  they  being  as 

* [We  have  observed  in  the  younor  African  lions  at  the  Zoological  Gardens 
that  the  inane  began  to  be  distinctly  developed  at  the  third  year,  and  was  com- 
pleted at  the  fourth.] 


84 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


perfect  as  in  any  hen  pheasant  that  is  not  in  the  least  prepared  for 
laying  eggs,  and  having  both  the  ovary  and  oviduct. 

As  t!ie  observations  hitherto  made  have  been  principally  upon 
birds  found  wild,  little  of  their  history  can  be  known  ; but  from 
what  took  place  in  a hen  pheasant,  in  the  possession  of  a friend 
of  Sir  Joseph  Banks,  it  appears  probable  that  this  change  of  cha- 
racter takes  place  at  an  advanced  period  of  the  animal’s  life,  and 
does  not  grow  up  with  it  from  the  beginning.  This  lady,  who 
had  for  some  time  bred  pheasants,  and  paid  particular  attention 
to  them,  observed  that  one  of  the  hens,  after  having  produced 
several  broods,  moulted,  when  the  succeeding  feathers  were  those 
of  a cock,  and  that  this  animal  was  never  afterwards  impregnated. 
Hence  it  is  most  probable  that  all  the  hen  pheasants  found  wild, 
having  the  feathers  of  a cock,  were  formerly  perfect  hens,  but  have 
been  changed  by  age,  or  perhaps  by  certain  constitutional  cir- 
cumstances.* 

Having  bought  some  pheasants  from  a dealer  in  birds,  among 
which  were  several  hens,  I perceived,,  the  year  after,  that  one  of 
the  hens  did  not  lay,  and  that  she  began  to  change  her  feathers. 
The  year,  following  she  had  nearly  the  plumage  of  the  cock,  but 
less  brilliant,  especially  on  the  head  ; and  it  is  more  than  probable 
that  this  was  an  old  hen,  nearly  under  circumstances  similar  to 
to  those  before  described. 

Lady  Tynte  had  a favourite  pied  pea-hen  which  had  produced 
chickens  eight  several  times  ; having  moulted  when  about  eleven 
years  old,  the  lady  and  family  were  astonished  by  her  displaying 
the  feathers  peculiar  to  the  other'  sex,  and  appeared  like  a pied 
peacock.  In  this  process  the  tail,  which  became  like  that  of  the 
cock,  first  made  its  appearance  after  moulting  ; and  in  the  following 
year,  having  moulted  again,  produced  similar  feathers.  In  the  third 
year  she  did  the  same,  and,  in  addition,  had  spurs  resembling  those 
of  a cock.  She  never  bred  after  this  change  in  her  plumage,  and 
died  in  the  following  winter  during  the  hard  frost  in  the  year  1775-6. 
This  bird  is  now  preserved  in  the  museum  of  the  late  Sir  Ashton 
Lever.f 

From  what  has  been  related  of  these  three  birds,  we  may  con- 

* [The  cause  of  the  change  in  the  plumage  which  Mr.  Hunter  here  alludes  to, 
has  been  proved  by  subsequent  dissections  to  be  effective  and  not  uncommon.  See 
the  paper  entitled  ‘On  the  change  in  the  Plumage  of  some  Hen-Pheasants,’  by 
Wm.  Yarrell,  Esq.,  Phil.  Trans.  1827,  in  which  the  author  states,  that  “certain 
constitutional  circumstances  producing  this  change  may,  and  do  occur,  at  any 
period  during  the  life  of  the  fowl,  and  that  they  can  be  produced  by  artificial 
means.”] 

I It  might  be  supposed  that  this  bird  was  really  a cock  which  had  been  sub- 
stituted for  the  hen  ; but  the  following  facts  put  this  matter  beyond  a doubt. 
First,  there  was  no  oilier  pied  pea-fowl  in  the  country./  Secondly,  the  hen  had 
nobs  on  her  toes,  which  were  the  same  after  her  change.  Thirdly,  she  was  as 
small  after  the  change  as  before,  therefore  too  small  for  a cock.  Fourthly,  she 
was  a favourite  bird,  and  was  generally  fed  by  the  lady,  and  used  to  come  for  her 
food,  which  she  still  continued  to  do  after  the  change  in  the  feathers. 


OF  THE  OVARIA. 


85 


dude,  that  this  change  is  merely  the  effect  of  age,  and  obtains  to  a 
certain  degree  in  every  class  of  animals.  We  find  something  similar 
taking  place  even  in  the  human  species ; for  that  increase  of  hair 
observable  on  the  faces  of  many  women  in  advanced  life  is  an  ap- 
proach towards  the  beard,  which  is  one  of  the  most  distinguishing 
secondary  properties  of  man. 

Thus  we  see  the  sexes  which,  at  an  early  period,  had  little  to 
distinguish  them  from  each  other,  acquiring  about  the  time  of 
puberty  secondary  properties,  which  clearly  characterize  the  male 
and  female,  the  male  at  this  time  receding  from  the  female,  and  as- 
suming the  secondary  properties  of  his  sex. 

The  fe.male,  at  a much  later  time  of  life,  when  the  powers  of  pro- 
pagation cease,  loses  many  of  her  peculiar  properties,  and  may  be 
said,  except  from  mere  structure  of  parts,  to  be  of  no  sex,  even  re- 
ceding from  the  original  character  of  the  animal,  and  approaching, 
in  appearance,  towards  the  male,  or  perhaps  more  properly  towards 
the  hermaphrodite. 


5.  AN  EXPERIMENT  TO  DETERMINE  THE  EFFECT  OF 
EXTIRPATING  ONE  OVARIUM  UPON  THE  NUMBER 
OF  YOUNG  PRODUCED.^ 

lx  all  animals  of  distinct  sex,  the  females,  those  of  the  Bird-kind 
excepted,  have,  I believe,  two  ovaria,  and  of  course  the  oviducts  are 
in  pairs. 

By  distinct  sex  I mean  when  the  parts  destined  to  the  purposes 
of  generation  are  of  two  kinds,  each  kind  appropriated  to  an  in- 
dividual of  each  species,  distinguished  by  the  appellation  of  male  and 
female,  and  equally  necessary  to  the  propagation  of  the  animal. 
The  testicles,  with  their  appendages,  constitute  the  Axiale ; the 
ovaria,  and  their  appendages,  the  female  sex. 

As  the  ovaria  are  the  organs  which,  on  the  part  of  the  female, 
furnish  what  is  necessary  towards  the  production  of  the  third,  or 
young  animal,  and  as  females  appear  to  have  a limited  portion  of 
the  middle  stage  of  life  allotted  for  that  purpose,  it  becomes  a question, 
whether  those  organs  are  worn  out  by  repeated  acts  of  propaga- 
tion ; or  whether  there  is  not  a natural  and  constitutional  period  to 
that  power  on  their  part,  even  if  such  power  has  never  been  exerted  ? 
If  we  consider  this  subject  in  every  view,  taking  the  human  species 
as  an  example,  we  shall  discover  that  circumstances,  either  local  or 
constitutional,  may  be  capable  of  extinguishing  in  the  female  the 
faculty  of  propagation.  Thus  we  may  observe  when  a woman 
begins  to  breed  at  an  early  period,  as  at  fifteen,  and  has  her  children 


* [Originally  published  in  the  Philosophical  Transactions,  vol.  Ixxvii.,  p.  233  ; 
read,  March  22,  1787.] 

9 


86 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


fast,  that  she  seldom  breeds  longer  than  the  age  of  thirty  or  thirty- 
five;  therefore  we  may  suppose  either  that  the  parts  are  then  worn 
out,  or  that  tlie  breeding  constitution  is  over.  If  a woman  begins 
later,  as  at  twenty  or  twenty-five,  she  may  continue  to  breed  to  the 
age  of  forty  or  more:  and  there  are,  now  and  then,  instances  of 
women  who,  not  having  conceived  before,  have  had  children  as 
late  in  life  as  at  fifty  years  or  upwards.  After  that  period  few 
women  breed,  even  though  they  should  not  liave  bred  before; 
therefore  there  must  be  a natural  period  to  the  power  of  concep- 
tion. A similar  stop  to  propagation  may  likewise  take  place  in 
other  classes  of  animals,  probably  in  the  female  of  every  class,  the 
period  varying  according  to  circumstances.  But  still  we  are  not 
enabled  to  determine  how  far  it  depends  on  any  particular  property 
of  the  constitution,  or  of  the  ovarium  alone. 

As  the  female,  in  most  classes  of  animals,  has  two  ovaria,  I 
imagined  that  by  removing  one  it  might  be  possible  to  determine 
how  far  their  actions  w'ere  reciprocally  influenced  by  each  other, 
from  the  changes  which  by  comparison  might  be  observed  to  take 
place,  either  by  the  breeding-period  being  shortened,  o-r  perhaps,  in 
those  animals  whose  nature  it  is  to  bring  forth  more  than  one  at  a 
time,  by  the  number  produced  at  each  birth  being  diminished. 

There  are  two  views  in  which  this  subject  may  be  considered. 
The  first,  that  the  ovaria,  when  properly  employed,  may  be  bodies 
determined  and  unalterable  respecting  the  number  of  young  to  be 
produced.  In  this  case  we  can  readily  imagine  that,  when  one 
ovarium  is  removed,  the  other  may  be  capable  of  producing  its 
determined  number  in  two  different  ways  : one,  when  the  i-emain- 
ing  ovarium,  not  influenced  by  the  loss  of  the  other,  will  produce 
its  allotted  number,  and  in  the  same  time;  the  other,  when  affected 
by  the  loss,  yet  the  constitution  demanding  the  same  number  of 
young  each  time  of  breeding,  as  if  there  w'ere  still  two  ovaria  ; it 
must  furnish  double  the  number  it  would  have  been  required  to 
supply  had  both  been  allowed  to  remain,  but  must  consequently 
cease  from  the  performance  of  its  function  in  half  the  time.  The 
second  view  of  the  subject  is,  by  supposing  that  there  is  not 
originally  any  fixed  number  which  the  ovarium  must  produce,  but 
that  the  number  is  increased  or  diminished  according  to  circum- 
stances; that  it  is  rather  the  constitution  at  large  that  determines 
the  number;  and  that  if  one  ovarium  is  removed,  the  other  will  be 
called  upon  by  the  constitution  to  perform  the  operations  of  both, 
by  which  means  the  animal  should  produce  with  one  ovarium  the 
same  number  of  young  as  would  have  been  produced  if  both  had 
remained. 

With  an  intention  to  ascertain  those  points  as  far  as  I could,  I 
was  led  to  make  the  following  experiment;  and  for  that  purpose 
gave  pigs  a preference  to  any  other  animal,  as  being  easily 
managed,  producing  several  at  a litter,  and  breeding  perfectly  well 
under  the  confinement  necessary  for  experiments.  I selected  two 
females  of  the  same  colour  and  size,  and  likewise  a boar-big,  all  of 
the  same  farrow;  and,  having  removed  an  ovarium  from  one  of 


OF  THE  OVARIA. 


87 


the  females,  I cut  a slit  in  one  ear  to  distinguish  it  from  the  other. 
They  were  well  fed  and  kept  warm,  that  there  might  be  no  impedi- 
ment to  their  breeding;  and  whenever  they  farrowed,  their  pigs 
were  taken  away  exactly  at  the  same  age. 

About  the  beginning  of  the  year  1779  they  both  took  the  boar  ; 
the  one  which  had  been  spayed  earlier  than  the  perfect  female. 
The  distance  of  time,  however,  was  not  great,  and  they  continued 
breeding  at  nearly  the  same  times.  The  spayed  animal  continued 
to  breed  till  September  1783,  when  she  was  six  years  old,  which 
was  a space  of  more  than  four  years.  In  that  time  she  had  eight 
farrows ; but  did  not  take  the  boar  afterwards,  and  had  in  all 
seventy-six  pigs.  The  perfect  one  continued  breeding  till  Decem- 
ber 1785,  when  she  was  about  eight  years  old,  a period  of  almost 
six  years,  in  which  time  she  had  thirteen  farrows,  and  had  in  all 
one  hundred  and  sixty-two  pigs;  after  this  time  she  did  not  breed  : 
I kept  her  till  November  1786. 

I have  here  annexed  a table  of  the  different  times  of  each  farrow, 
with  the  number  of  pigs  produced. 


Spayed  Sow. 

Farrows. 

Number  cf  young. 

Time. 

1 

6 

Dec. 

1779. 

2 

8 

July 

1780. 

3 

6 

Jan. 

1781. 

4 

10 

Aug. 

1781, 

5 

10 

Mar. 

1782. 

6 

9 

Sept. 

1782. 

7 

14 

IMay 

1783. 

8 

13 

Sept. 

1783. 

76 

November  following  she  was  put  to  the  boar,  but  brought  no 
pigs.  April  1784,  she  was  again  put  to  the  boar,  without  effect, 
and  never  was  observed  to  take  the  boar  afterwards,  although 
often  with  him.  November  1784,  she  was  killed. 


Perfect  Sow. 


Farrows. 

Number  of  young. 

Time. 

1 

9 

2 

6 

3 

8 

4 

13 

Dec.  1781. 

5 

10 

June  1782. 

6 

16 

Dec.  1782. 

7 

13 

June  1783. 

8 

12 

Oct.  1783. 

87 

Eleven  pigs  more  than  were  produced  by  the  spayed  sow  in  her 
eight  farrows. 


88 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


Time. 

Feb.  1784. 
June  1784. 
Dec.  1784. 
May  1785. 
Dec.  1785. 


87 

75 


Total  . 1G2 

The  number  from  the  spayed  one  . . 76 

More  than  farrowed  by  the  imperfect  animal  . . 86 

It  is  observable  that  both  sows  rather  increased  in  their  number 
each  time  as  they  grew'  older,  although  not  uniformly ; the  differ- 
ence between  the  first  and  last  in  both  animals  being  considerable. 

From  the  above  table  we  find  that  the  sow  with  only  one  ovarium 
bred  till  she  was  six  years  old,  from  the  latter  end  of  1779  till  Sep- 
tember 1783,  about  four  years,  and  in  that  time  brought  forth 
seventy-six  pigs.  The  perfect  animal  bred  till  she  was  eight  years 
of  age  ; and  if  conception  depended  on  the  ovari,  we  might  have 
expected  that  she  would  bring  forth  double  the  number  at  each 
birth  ; or,  if  not,  that  she  would  continue  breeding  for  double  the 
time.  We  indeed  find  her  producing  ten  more  than  double  the 
number  of  the  imperfect  animal,  although  she  had  not  doublb  the 
number  of  farrows ; but  this  may  perhaps  be  explained  by  observing 
that  the  number  of  young  increased  as  the  female  grew  older,  and 
the  perfect  sow  continued  to  breed  much  longer  than  the  other. 

From  a circumstance  mentioned  in  the  course  of  this  experiment 
it  appears  that  the  desire  for  the  male  continues  after  the  power  of 
breeding  is  exhausted  in  the  female  ; and  therefore  does  not  alto- 
gether depend  on  the  pow'crs  of  the  ovaria  to  propagate,  although 
it  may  probably  be  influenced  by  the  existence  of  such  parts. 

If  these  observations  should  be  considered  as  depending  on  a 
single  experiment,  from  which  alone  it  is  not  justifiable  to  draw 
conclusions,  I have  only  to  add  that  the  difference  in  the  number 
of  pigs  produced  by  each  w'as  greater  than  can  be  justly  imputed 
to  accident,  and  is  a circumstance  certainly  in  favour  of  the  uni- 
versality of  the  principle  I wished  to  ascertain.* 

From  this  experiment  it  seems  most  probable  that  the  ovaria  are 

* It  may  be  thought  by  some  that  I should  have  repeated  this  experiment;  but 
an  annual  expense  of  twenty  pounds  for  ten  years,  and  the  necessary  attention 
to  make  the  experiment  complete,  will  be  a sufficient  reason  for  my  not  having 
done  it. 


Farrows. 

Number  of  youni 

9 

12 

10 

16 

11 

12 

12 

16 

13 

19 

75 

After  which  she  bred  no  more. 

The  first  eight  farrow's  were 
The  last  five  farrows  were  . 


DESCRIPTION  OF  THE  UTERUS,  ETC. 


89 


from  the  beginning  destined  to  produce  a fixed  number,  beyond 
which  they  cannot  go,  although  circumstances  may  tend  to  diminish 
that  number ; but  that  the  constitution  at  large  has  no  power  of 
giving  to  one  ovarium  the  power  of  propagating  equal  to  both  ; for 
in  the  present  experiment  the  animal  with  one  ovarium  produced 
ten  pigs  less  than  half  the  number  brought  forth  by  the  sow  with 
both  ovaria.  But  that  the  constitution  has  so  far  a power  of  influ- 
encing one  ovarium  as  to  make  it  produce  its  number  in  a less  time 
than  would  probably  have  been  the  case  if  both  ovaria  had  been 
preserved,  is  to  be  inferred  from  the  above-recited  experiment. 


6.  THE  CASE  OF  A YOUNG  WOMAN  WHO  POISONED 
HERSELF  IN  THE  FIRST  MONTH  OF  HER  PREG- 
NANCY. 

BY  THOMAS  OGLE,  SURGEOX,  GREAT  RUSSELL-STREET,  BLOOMSBURY. 

To  which  is  added,  an  Account  of  the  Appearances  after  Death;  by 
the  late  John  Hunter.* 

Mary  Hunt,  servant  to  a gentleman  in  Charlotte-street,  Bedford- 
square,  twenty-five  years  of  age,  had  for  some  time  shown  a par- 
tiality for  one  of  the  footmen  in  the  same  family.  She  became  all 
at  once  exceedingly  dejected,  which  was  supposed  to  proceed  from 
his  neglecting  her;  and  on  Thursday,  the  19th  of  April,  at  twelve 
o’clock  at  night,  took  half  an  ounce  of  white  arsenic,  and  imme- 
diately afterwards  drank  a quart  of  wine;  about  one  o’clock 
she  had  so  much  pain  in  her  stomach  as  to  be  obliged  to  call  for 
assistance. 

The  symptoms  were  excruciating  pain  in  the  stomach,  sick- 
ness, vomiting,  excessive  thirst,  and  a small  tremulous  pulse ; 
these  were  followed  by  pain  in  the  bowels,  and  several  purging 
stools. 

She  drank  brandy  and  water,  wine  and  water,  and  several  quarts 
of  plain  water,  to  relieve  the  thirst  and  ease  the  pain.  Some 
hours  after  taking  the  arsenic  she  became  easier,  expressed  a desire 
to  be  left  alone,  being  inclined  to  sleep,  and  remained  several  hours 
in  a dosing  or  comatose  state,  from  which  she  did  not  recover,  and 
died  about  one  o’clock  on  Friday,  thirteen  hours  after  taking  the 
arsenic. 

Upon  inspecting  the  body  after  death  there  were  found  the  fol- 
lowing appearances. 

* [Originally  published  in  the  Transactions  of  a Society  for  the  Improvement 
of  hledical  and  Chirurgical  Knowledge,  vol.  ii.,  p.  63.  Communicated  to  the 
Society  by  Everard  Home,  and  read  August  5,  1794.] 

9* 


90 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


In  the  cavity  of  the  abdomen  there  "W'as  an  appearance  of  the 
effects  of  slight  inflammation  on  the  peritoneal  coat  of  the  small 
intestines. 

The  stomach  contained  a greenish  fluid,  with  a curdy  substance  in 
it,  in  all  amounting  to  about  twelve  ounces. 

On  the  internal  surface  of  the  great  curvature  near  the  cardiac 
a portion  of  the  villous  coat,  about  the  size  of  a crown-piece,  was 
partly  destroyed,  and  of  a dark  red  colour,  with  a regularly- 
defined  edge,  and  some  of  the  arsenic  adhering  to  different 
parts  of  its  surface.  The  rest  of  the  stomach  was  in  a natural 
state.  This  appearance  in  the  stomach  was  an  effect  produced  by 
the  arsenic.  ' 

The  uterus  was  a little  enlarged,  and  had  the  vessels  unusually 
loaded  with  red  blood. 

There  was  an  uncommon  quantity  of  blood  in  the  vessels  of  the 
ovaria  and  Fallopian  tubes,  but  principally  in  those  of  the  ovarium, 
and  morsus  diaboli  of  the  left  side. 

The  organs  of  generation  being  carefully  removed,  and  both 
ovaria  being  slit  open,  there  was  found  in  the  left  a corpus  luteum. 

It  was  evident,  from  this  circumstance,  that  conception  had  taken 
place  ; which  led  to  an  inquiry  respecting  the  last  appearance  of 
her  menses,  which  appeared  by  the  evidence  of  the  family  to  have 
been  little  more  than  a month  before  her  death. 

With  the  dread  upon  her  mind  of  being  with  child,  the  usual 
period  of  menstruation  had  hardly  elapsed  without  its  appearing, 
which  confirmed  her  suspicions,  before  she,  in  a fit  of  despair,  put 
an  end  to  her  life. 

From  this  evidence,  the  period  of  conception  could  not  exceed  a 
month,  and  probably  was  much  within  that  time. 

As  it  was  interesting  to  have  the  parts  accurately  examined,  to 
see  what  information  might  be  acquired  respecting  the  fmtus  at  so 
early  a period,  they  were  given  to  Mr.  Hunter  for  that  purpose, 
w'hose  observations  upon  them  are  contained  in  the  following 
account. 

The  arteries  of  the  uterus  were  injected,  and  the  smaller  vessels 
were  filled  to  so  great  a degree  of  minuteness  that  the  whole  sur- 
face became  extremely  red. 

The  cervix  uteri  and  os  tincce  \vere  of  their  natural  size  ; but  the 
body,  or  that  portion  of  the  uterus  next  the  fundus,  was  a little  en- 
larged, and  more  prominent  externally  in  the  middle.  The  sper- 
matic vessels  were  also  enlarged. 

On  cutting  into  the  substance  of  the  uterus,  it  had  more  of  a 
laminated  structure  than  in  the  unimpregnated  state;  this  appear- 
ance of  lamellee  appeared  upon  examination  to  be  formed  by  veins 
somewhat  enlarged,  compressed  and  transversely  divided.  The 
uterus  was  unsually  soft  in  texture,  and  terminated  on  the  internal 
surface  in  a pulpy  substance. 

The  blood-vessels  of  the  uterus  passed  into  and  ramified  upon 
this  pulpy  substance,  which  was  continued  across  at  the  cervix 


DESCRIPTION  OF  THE  UTERUS,  ETC. 


91 


uteri,  so  as  to  make  the  cavity  of  the  uterus  a circumscribed  bag  ; 
and  at  this  part  the  pulpy  substance  was  so  thin  as  to  resemble  the 
retina. 

This  cavity  had  a smooth  but  irregular  internal  surface,  and  the 
pulpy  substance  upon  which  it  was  formed  was  evidently  blood 
coagulated  and  varied  in  its  thickness  in  different  parts.  Upon  a 
longitudinal  section  of  the  uterus,  the  posterior  part  of  tlie  coagulum, 
which  was  the  thickest,  was  nearly  half  an  inch;  where  it  termi- 
nated towards  the  cervix  it  was  pendulous  and  unattached.  There 
were  also  several  loose  processes,  all  turned  towards  the  cervix,  one 
of  them  very  thin,  as  broad  as  a silver  penny,  and  only  attached 
by  one  edge  to  the  fundus  near  the  opening  of  the  right  Fallopian 
tube. 

On  slitting  open  tbe  Fallopian  tubes,  the  coagulum  was  found  to 
pass  some  way  into  them,  and  to  extend  more  than  half  an  inch 
on  the  left  side,  which  had  the  corpus  luteum.  The  coagulum  was 
thickest  at  the  orifice  of  the  tube,  and  there  adhered  to  the  inner 
surface  for  the  eighth  part  of  an  inch;  beyond  which  it  became 
smaller  and  terminated  in  a point.  In  the  left  tube  the  coagulum 
was  in  two  places  coiled  or  folded  upon  itself,  as  if  thrown  back 
by  the  action  of  the  tube.  The  portions  of  the  coagulum  at  the 
orifices  of  the  tubes  were  hollow. 

When  the  inner  surface  of  the  cavity  of  the  uterus  was  examined 
with  a magnifying  glass  it  was  found  extremely  vascular,  and 
dotted  with  innumerable  whitish  spots  too  small  to  be  seen  by  the 
naked  eye. 

In  the  examination  of  this  uterus  and  Fallopian  tubes,  as  Mr. 
Hunter’s  chief  object  was  the  detection  of  the  embryo,  no  precau- 
tion was  omitted  which  could  be  devised  to  prevent  it  being  over- 
looked or  destroyed. 

The  uterus  was  opened  in  a bason  of  clear  water,  the  incision 
was  conducted  with  great  circunsspection,  and  very  slowly  con- 
tinued, till  the  whole  of  the  cavity  was  exposed.  Every  part  of 
the  internal  surface  was  minutely  examined  with  magnifying 
glasses;  but  in  no  situation  was  there  anything  resembling  an 
embryo  to  be  found. 

The  presence  of  a corpus  luteum,  the  enlargement  of  the  uterus, 
the  newly-formed  vascular  membrane,  or  decidua,  lining  the  cavity, 
and  the  history  of  the  case,  sufficiently  prove  conception  to  have 
taken  place  ; and  the  embryo  being  nowhere  detected  by  an  exa- 
mination so  accurate  and  conducted  by  an  anatomist  so  skilful  in 
minute  investigation,  would  induce  a belief  that  the  foetus  had  not 
been  sufficiently  advanced  to  take  on  a regular  form. 

The  appearances  in  the  uterus,  here  described,  the  late  Dr. 
Hunter,  in  his  lectures,  mentioned  to  have  seen  at  a very  early 
period  after  impregnation  : so  far  they  are  not  entirely  new.  The 
accuracy  of  the  examination  renders  this  case  valuable,  as  it  seems 
to  enable  us  to  decide  a point  hitherto  not  at  all  understood — that 
certain  changes  in  the  uterus  not  only  take  place  previous  to  the 


92 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


reception  of  the  foetus,  but  that  the  foetus  does  not  acquire  a visible 
form  for  some  time  after  these  clianges  have  been  made.* 

* [The  positive  conclusions  deduced  from  tliis  case,  viz.,  that  certain  changes 
take  place  in  the  uterus  within  one  month  after  conception,  have  been  confirmed 
by  all  those  anatomists  who  have  enjoyed  similar  opportunities  of  examining-  the 
uterine  organs  within  the  same  period.  These  changes  consist  essentially  in  the 
effusion  of  fibrin  or  coagulable  lymph  from  the  villi  of  the  lining  membrane  of  the 
uterus,  which  villi  also  become  much  elongated  and  highly  vascular;  and  minute 
vessels  are  continued  from  them  into  the  effused  lymph,  forming  loops  or  arches 
in  that  substance.  This  process  is  compared  by  Hunter,  in  the  following  paper, 
to  the  effusion  of  lymph  consequent  on  the  introduction  of  an  extraneous  living 
part  into  any  of  the  cavities  of  the  body;  and  Professor  von  Baer,  in  a recent 
elaborate  description  of  the  uterus  of  a female  who  drowned  herself  eight  days 
after  impregnation,  makes  the  same  comparison.  I’rofessor  Weber,  in  an  exami- 
nation of  the  uterus  seven  days  after  conception,  also  speaks  of  the  great  vascu- 
larity of  its  inner  surface,  and  describes  the  villi  as  consisting  of  small  cylinders 
placed  perpendicularly  to  the  inner  surface  of  the  uterus,  united  by  a slimy  mem- 
brane, and  forming  together  a layer  of  a pale  soft  substance,  from  half  a line  to  a 
line  in  thickness;  whilst  in  some  places  the  cylinder  presented  the  length  of  from 
two  to  three  lines. 

With  respect  to  the  negative  results  of  Mr.  Hunter’s  examination  relative  to 
the  reception  of  the  toetus  in  the  uterus,  and  “ its  acquisition  of  a visible  form,”  I 
suppose  that  the  word  ‘ foetus  ’ is  here  used  to  express  the  product  of  generation, 
or  ovum,  especially  as  it  is  stated,  that  “in  the  examination  of  the  uterus  and 
Fallopian  tubes  Mr.  Hunter’s  chief  object  was  the  detection  of  the  ‘embryo.’  ” 
Now  if  the  product  of  generation  were  really  expected  to  have  been  seen  in  that 
state  of  development  which  we  understand  by  the  terms  embryo  and  foetus,  its 
presence  was  most  likely  overlooked ; since,  from  the  analogy  of  the  dog  and 
rabbit,  it  most  probably  would  have  existed  merely  as  a small  pellucid  vesicle  or 
ovum,  supposing  that  it  had  escaped  from  the  ovarium;  and  it  is  to  be  regretted 
that  the  expression  “ there  was  found  in  the  left  ‘ovarium’  a corpus  luteum  ” is 
all  the  evidence  on  that  point  which  the  present  case  affords. 

In  the  bitch.  Von  Baer  has  shown  that  the  ova  pass  into  the  Fallopian  tubes  on 
the  eight  day  after  impregnation,  and  that  when  they  reach  the  uterus  they  lie 
quite  free  in  its  cavity,  are  perfectly  transparent,  of  a somewhat  elongated  form, 
and  extremely  delicate  texture,  and  are  from  half  a line  to  a third  of  a line  in 
diameter. 

In  the  rabbit,  the  observations  of  De  Graaf,  of  Prevost  and  Dumas,  and  ofCoste, 
prove  that  the  ova  pass  into  the  tubes  the  third  (or,  according  to  Coste,  the  second) 
day  after  impregnation ; they  reach  the  horns  of  the  uterus  on  the  fourth  day, 
and  are  then  about  a line  in  diameter,  in  the  form  of  pellucid  bubbles,  free  and 
moveable. 

According  to  Home,  the  human  ovum  has  reached  the  uterus  on  the  eighth  day- 
after  impregnation,  when  it  is  described  as  presenting  an  elliptical  form,  rather 
more  tlian  a line  parts  of  an  inch)  in  length,  and  parts  of  an  inch  in 
breadtli.  It  is  composed  of  two  membranes,  of  which  the  external  is  of  consider- 
able thickness  and  consistence,  very  little  transparent,  quite  smooth,  and  milk- 
white;  the  internal  membrane  or  bag  consist  ‘of  a seemingly  very  thin,  perfectly 
smooth,  and  glossy  membrane,  which  seemed  to  have  considerable  strength.’ 
This  internal  membrane  contained  a thick,  slimy  matter,  like  honey,  and  “two 
round  corpuscles,  apparendy  more  opake,  and  of  a yellowish  tint,”  regarded  as 
“ the  probable  seat  of  the  future  heart  and  brain.” 

On  comparing  the  precedingaccount  with  the  observations  that  have  been  made 
on  the  marnmilerous  ovum,  it  will  be  found  that  the  nearest  resemblance  to  the 
supposed  human  ovum  obtains  in  that  of  the  ornithorhynchus,  at  least  in  the  texture 
of  the  two  membranes  described,  of  which  the  external  must  be  regarded  as  the 
chorion,  the  internal  as  the  membrana  vitelli.  In  the  ornithorhynchus,  as  in  the 
ovo-viviparous  reptiles,  the  chorion  is  dense  and  unyielding  ; but  m the  specimens 


ON  THE  STRUCTURE  OF  THE  PLACENTA. 


93 


7.  ON  THE  STRUCTURE  OF  THE  PLACENTA. 

The  connexion  between  the  mother  and  fetus  in  the  human  sub- 
ject, has  in  every  age,  in  which  science  has  been  cultivated,  called 
forth  the  attention  of  the  anatomist,  the  physiologist,  and  even  the 
philosopher;  but  both  that  connexion,  and  the  structure  of  the  parts 
which  form  the  connexion,  were  unknown  till  about  the  year  1754. 
The  subject  is  certainly  most  interesting,  and  the  discovery  infi- 
portant ; and  it  is  my  intention,  in  the  following  pages,  to  give  such 
an  account  of  it  as  I hope  may  be  acceptable  to  the  public  while, 
at  the  same  time,  I establish  my  own  claim  to  the  discovery.  But 
that  I may  not  seem  to  arrogate  to  myself  more  merit  than  I am 
entitled  to,  let  me  in  justice  to  another  person  relate  what  follows. 

The  late  indefatigable  Ur.  MacKenzie,  about  the  month  of  May, 
1754,  when  assistant  to  Dr.  Smellie,  having  procured  the  body  of 
a pregnant  woman,  who  died  undelivered  at  the  full  term,  had  in- 
jected both  the  veins  and  arteries  with  particular  success,  the  veins 
being  filled  with  yellow,  the  arteries  with  red.f 

Having  opened  the  abdomen,  and  exposed  the  uterus,  he  made 
an  incision  into  the  fore  part,  quite  through  its  substance,  and  came 

which  we  examined,  and  which,  as  in  Sir  Everard  Home’s  case,  had  been  subjected 
to  the  action  of  spirit,  the  chorion  was  semitransparent.  In  those  mammalia, 
however,  which  approximate  the  human  species  in  the  placental  development  of 
the  foetus,  the  ovum,  when  it  has  been  detected  unattached  in  the  uterus,  has 
invariably  presented  a translucency  and  delicacy  of  its  membranes,  with  which 
the  structure  of  the  human  ovum,  as  described  by  Home,  is  totally  at  variance; 
■and,  from  the  tenor  of  the  whole  account,  we  believe  the  object  to  have  been 
what  Mr.  Bauer,  to  whom  its  description  and  delineation  were  confided,'^  declared 
it  to  resemble,  viz.,  the  egg  of  an  insect. 

Rejecting,  then,  the  description  we  have  just  been  considering, — and  its  apo- 
cryphal character  is  rightly  admitted  by  all  physiologists  of  the  present  day,  who 
have  investigated  the  nature  of  the  mammiferous  ovum, — the  determination  of  the 
period  of  the  passage  of  the  human  ovum  into  the  uterus  after  impregnation,  and 
its  condition  and  structure  when  first  received  into  that  cavity,  still  remain  open 
to  the  researches  of  the  physiologist.] 

* This  paper  was  read  at  the  Royal  Society,  but  as  the  facts  had  before  that 
time  been  given  to  the  public,  it  was  not  published  in  the  Philosophical  Transac- 
tions. 

f Dr.  MacKenzie  being  then  an  assistant  to  the  late  Dr.  Smellie,  the  procuring 
and  dissecting  this  woman  without  Dr.  Smellie’s  knowledge  was  the  cause  of  a 
separation  between  them,  for  the  leading  steps  to  such  a discovery  could  not  be 
kept  a secret.  The  winter  following  Dr.  MacKenzie  began  to  teach  midwifery 
in  the  Borough  of  Southwark. 


^ “ As  the  ovum  was  so  extremely  small  as  to  admit  of  dispute  whether  it  was 
one  or  not,  I carried  it  immediately  to  Kew,  to  Mr.  Bauer,  who,  after  examining 
it,  said  it  looked  like  the  egg  of  an  insect.” — Phil.  Trans.,  p.  255. 

• Mr.  Clift  who  laid  open  the  uterus  in  question,  and  patiently  scrutinized  the 
whole  of  its  cavity  without  perceiving  any  trace  of  an  ovum,  has  always  been  of 
opinion  that  the  one  afterwards  detected  by  Home  was  dropped  from  one  of  the 
numerous  flesh-flies  which  were  buzzing  about  at  the  time  of  the  examination. 


94 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


to  what  seemed  to  be  an  irregular  mass  of  injected  matter.  The 
appearance  being  new  he  proceeded  no  further,  and  greatly  obliged 
me,  by  desiring  my  attendance  to  examine  parts,  in  which  the 
appearances  were  so  uncommon.  The  examination  was  made  in 
his  presence,  and  in  the  presence  of  several  other  gentlemen, 
whose  names  I have  now  forgotten  ; but  I have  reason  to  believe 
that  some  are  settled  in  this  country,  who  I hope  will  have  an  oppor- 
tunity of  perusing  this  publication.* 

I first  raised,  with  great  care,  a part  of  the  uterus  from  the  irre- 
gular mass,  and  in  doing  this  observed  regular  pieces  of  wax  passing 
obliquely  between  it  and  the  uterus,  which  broke  off,  leaving  part 
attached  to  that  mass;  and  on  attentively  examining  the  portions 
towards  the  uterus,  they  plainly  appeared  to  be  a continuation  of 
the  veins  passing  from  it  to  this  substance,  which  proved  to  be  pla- 
centa. 

I likewise  observed  other  vessels,  about  the  size  of  a crow-quill, 
passing  in  the  same  manner,  although  not  so  obliquely  ; these  also 
broke  upon  separating  the  placenta  and  uterus,  leaving  a small  portion 
on  the  surface  of  the  placenta  ; and  on  examination  they  were  disco- 
vered to  be  continuations  of  the  a rteries  of  the  uterus.  My  next  step  was 
to  trace  these  vessels  into  the  substance  of  what  ajipeared  placenta, 
which  was  first  attempted  in  a vein;  but  that  soon  lost  the  regular- 
ity of  a vessel,  by  terminating  at  once  upon  the  surface  of  the  pla- 
centa in  a very  fine  spongy  substance,  the  interstices  of  which  were 
filled  with  the  yellow  injected  matter.  This  termination  being  new, 
I I’epeated  the  same  kind  of  examination  on  other  veins,  which  al- 
ways led  me  to  the  same  terminations,  never  entering  the  substance 
of  the  placenta  in  the  form  of  a vessel.  I then  examined  the  arte- 
ries, tracing  them  in  the  same  manner  towards  the  placenta,  and 
found  that,  having  made  a twist,  or  close  spiral  turn  upon  themselves, 
they  were  lost  on  its  surface.  On  a more  attentive  view,  I per- 
ceived that  they  terminated  in  the  same  way  as  the  veins  ; for  op- 
posite to  the  mouth  of  the  artery  the  spongy  substance  of  the  pla- 
centa was  readily  distinguished  with  the  red  injection  intermixed. 

Upon  cutting  into  the  placenta  I discovered,  in  many  places  of  its 

* If  I shnuld  be  so  fortunate  as  to  have  tliis  publication  fall  into  any  of  those 
gentlemen’s  hands,  I hope  they  will  favour  me  with  their  opinion  of  my  state  of 
the  facts,  which  led  to  the  discovery. 

It  may  be  suspected  by  some  (but  none  I hope  to  whom  I have  the  pleasure  of 
being  known,)  that  I am  not  doing  Dr.  MacKenzie  justice,  and  am  perhaps  sup- 
pressing some  part  of  that  share  of  the  discovery  to  which  he  is  entitled.  This 
idea  (if  ever  it  should  arise),  I may  probably  not  be  able  to  remove;  but  1 hope 
it  will  also  be  seen  that  I myself  have  given  rise  to  it ; believing,  if  I had  been 
so  inclined,  that  I might  have  suppressed  Dr.  MacKenzie’s  name  altogether 
without  ever  running  the  hazard  of  being  detected.  I was  indeed  so  tenacious  of 
my  claim  to  the  discovery,  that  I wrote  this  account  in  Dr.  MacKenzie’s  lifetime, 
with  a design  to  publish  it;  and  often  communicated  my  intentions  to  Dr.  George 
Fordyce,  who  1 knew  was  very  intimate  with  the  Doctor,  in  consequence  of  both 
teaching  in  the  same  place,  and  making  many  experiments  together;  therefore  he 
is  a kind  of  collateral  witness,  that  what  I now  publish  is  the  same  account 
which  I gave  in  Dr,  MacKenzie’s  lifetime. 


ON  THE  STRUCTURE  OF  THE  PLACENTA. 


95 


substance,  yellow  injection,  in  others  red,  and  in  many  others  these 
two  colours  mixed.  The  substance  of  the  placenta,  now  filled  with 
injection,  had  nothing  of  the  vascular  appearance,  nor  that  of  extra- 
vasation, but  had  a regularity  in  its  form  which  showed  it  to  be 
naturally  of  a cellular  structure,  fitted  to  be  a reservoir  for  blood. 

I perceived,  likewise,  that  the  red  injection  of  the  arteries  (which 
had  been  first  injected),  had  passed  out  of  the  substance  of  the  pla- 
centa into  some  of  the  veins  leading  from  the  placenta  to  the  uterus, 
mixing  itself  with  the  yellow  injection  ; and  that  the  spongy  chorion, 
called  the  decidua  by  Dr.  Hunter,  was  very  vascular,  its  vessels 
going  to  and  from  the  uterus,  being  filled  with  the  different  coloured 
injections. 

After  having  considered  these  appearances,  it  was  not  difficult 
for  me  to  determine  the  real  structure  of  the  placenta  and  course  of 
the  blood  in  these  parts:  but  Ahe  company,  prejudiced  in  favour  of 
former  theories,  combated  my  opinion  ; and  it  was  even  disputed 
whether  or  not  these  curling  arteries  could  carry  red  blood.  After 
having  dissected  the  uterus,  with  the  placenta  and  membranes,  and 
made  the  whole  into  preparations,  tending  to  show  the  above  facts, 
I returned  home  in  the  evening,  and  communicating  what  I had  dis- 
covered to  my  brother.  Dr.  Hunter,  who  at  first  treated  it  and  me 
with  good-humoured  raillery ; but  on  going  wdth  me  to  Dr.  Mac- 
Kenzie’s  he  was  soon  convinced  of  the  fact.  Some  of  the  parts 
were  given  to  him,  which  he  afterwards  showed  at  his  lectures,  and 
probably  they  still  remain  in  his  collection. 

Soon  after  this  time  Dr.  Hunter  and  I procured  several  placentae, 
to  discover  if  after  delivery,  the  termination  of  the  veins  and  the 
curling  arteries  could  be  observed  ; they  were  discernible  almost  in 
every  one  ; and  by  pushing  a pipe  into  the  placenta  we  could  fill  not 
only  its  whole  substance,  but  also  the  vessels  on  that  surface  which 
W'as  attached  to  the  uterus,  with  injection. 

The  facts  being  now  ascertained  and  universally  acknowledged, 
I consider  myself  as  having  a just  claim  to  the  discovery  of  the 
structure  of  the  placenta,  and  its  communication  with  the  uterus,  to- 
gether with  the  use  arisingfrom  such  structure  and  communication, 
and  of  having  first  demonstrated  the  vascularity  of  the  spongy  cho- 
rion. 

It  is  not  necessary  at  present  to  enter  into  the  various  opinions 
which  have  been  formed  on  this  subject;  because,  whatever  they 
W'ere,  they  could  not  be  just,  the  structure  of  the  parts  not  being 
known  : neither  shall  I endeavour  to  give  a complete  description 
of  alt  the  parts  immediately  connected  wdth  uterine  gestation,  but 
content  myself  with  describing  the  structure  of  the  placenta,  as  far 
as  it  has  any  relation  to  the  uterus  and  child ; and  wdth  explaining 
the  connexion  between  the  two^  leaving  the  reader  to  examine  wdiat 
has  been  said  upon  this  subject  by  others,  especially  by  Dr.  Hunter, 
in  that  very  accurate  and  elaborate  w'ork  which  he  has  published 
on  the  Gravid  Uterus,  in  which  he  has  minutely  described  and  ac- 
curately delineated  the  parts,  without  mentioning  the  mode  of  dis- 
covery, 


96 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  necessary  connexion  subsisting  in  all  animals  between  the 
mother  and  foetus,  for  the  nourishment  of  the  latter,  as  far  as  I know, 
takes  place  in  two  ways.  In  some  it  is  continued,  and  subsists 
through  the  whole  term  of  gestation  ; in  others  the  union  is  soon  dis- 
solved ; but  an  apparatus  is  provided,  which  at  once  furnishes  what 
is  sufficient  for  the  support  of  the  animal  till  it  comes  forth. 

The  first  of  these  are  the  viviparous,  the  second  the  oviparous 
animals,  both  of  which  admit  of  great  variety  in  the  mode  by  which 
the  same  effect  is  produced.*  In  the  first  division  is  included  the 
human  species,  which  alone  will  engage  our  present  attention.  But 
before  I describe  this  connexion,  it  may  be  necessary  that  the  rea- 
der should  understand  my  idea  of  generation:  I shall  therefore  re- 
fer him  to  what  I have  said  upon  that  subject  in  my  account  of  the 
free-martin.f 

In  the  human  species,  the  anatomical  structure  of  the  mother  and 
embryo,  relative  to  fcetation,  being  well  known,  it  will  only  be  neces- 
sary fully  to  describe  the  nature  of  the  connexion  between  them, 
which  is  formed  by  the  intermediate  substance  called  placenta.  For 
this  purpose  vve  must  first  consider  the  placenta  as  a common  part ; 
next,  the  uterus  as  belonging  to  the  mother,  yet  having  an  immediate 
connexion  with  the  placenta,  from  which  the  nourishment  of  the  foetus 
is  to  be  derived,  which  will  lead  us  lastly  to  a consideration  of  those 
peculiarities  of  structure  by  means  of  which  the  foetus  is  to  receive  its 
nourishment,  and  which  likewise  constitutes  its  immediate  commu- 
nication with  the  placenta.  It  is  the  structure  of  this  intermediate 
substance,  and  its  connexion  with  the  child  and  the  uterus  of  the 
mother,  which  have  hitherto  been  so  little  understood,  and  without 
any  accurate  knowledge  of  which  it  was  impossible  any  just  idea 
could  be  formed  of  its  functions. 

The  placenta  is  a mass  lying  nearly  in  contact  with  the  uterus  ; 
indeed  it  may  in  some  degree  be  said  to  be  in  continuity  with  a 
part  of  its  internal  surface.  On  the  side  applied  to  the  uterus  the 
placenta  is  lobulated,  having  deep  irregular  fissures.  It  is  probably, 
from  this  structure  of  the  placenta,  that  the  uterus  has  an  intestine 
motion  while  in  the  time  of  uterine  gestation,  not  an  expulsive  one; 
which  those  lobes  of  the  placenta  allow  of;  but  all  these  lobes  are  united 
into  one  uniform  surface  on  that  surface  next  to  the  child,  where  its 
umbilical  vessels  ramify.  When  w’e  cut  into  the  placenta  its  whole  sub- 
stance appears  to  belittle  else  than  a netw'ork, or  spongy  mass,  through 
which  the  blood-vessels  of  the  foetus  ramify,  and  indeed  seems  to  be 
principally  formed  by  the  ramifications  of  those  vessels ; it  exhibits 
hardly  any  appearance  of  connecting  membrane ; but  we  cannot  rea- 
dily suppose  it  to  be  without  such  a membrane,  as  there  is  so  much 

* It  may  be  remarked  here,  that  the  oviparous  admit  of  bein^  distinguished 
into  two  classes,  one  where  the  egg  is  hatched  in  the  belly,  as  in  the  viper,  which 
has  been  commonly  called  viviparous;  the  others,  where  the  eggs  have  been  first 
laid  and  then  hatched,  which  is  the  class  commonly  called  oviparous,  such  as  all 
the  bird  tribe : and  many  others,  as  snakes,  lizards,  &c. 

f See  page  70. 


ON  THE  STRUCTURE  OF  THE  PLACENTA. 


97 


regularity  in  its  texture.  The  cells,  or  interstices  of  each  lobe,  com- 
municate with  one  another,  even  much  more  freely  than  those  of 
the  cellular  membrane  in  any  other  part  of  the  body  ; so  that  what- 
ever fluid  will  pass  in  at  one  part,  readily  diffuses  itself  through  the 
whole  mass  of  lobe;  and  all  the  cells  of  each  lobe  have  a commu- 
nication at  the  common  base. 

This  structure  of  the  placenta,  and  its  reciprocal  communication 
with  the  two  bodies  with  which  it  is  immediately  connected,  form 
the  union  between  the  mother  and  foetus  for  the  support  of  the 
latter.  Prior  to  the  time  I have  mentioned  above,  anatomists  seem 
to  have  been  wholly  unacquainted  with  the  true  structure  of  placenta. 
By  notes  taken  from  Dr.  Hunter’s  lectures,  in  the  winter  1755-6,  it 
appears  that  he  expressed  himself  in  the  following  manner.’*’  “ The 
substance  of  the  placenta  is  a fleshy  mass,  which  seems  to  be  formed 
entirely  of  the  vessels  of  the  umbilical  rope.”  In  another  part,  men- 
tioning the  appearances  when  injected,  he  says:“  and  upon  a slight 
putrefaction  coming  on,  you  will  find  the  whole  appearing  like  a 
mass  of  vessels:”  then  says,  “there  is  always  a wbite  uninjected 
substance  between  the  vessels  ; but  whether  lymphatics  or  what  I 
cannot  tell.”  This  uninjected  substance,  mentioned  by  Dr.  Hunter, 
is  what  forms  the  cellular  structure. 

The  placenta  seems  to  be  principally  composed  of  the  ramifica- 
tions of  the  vessels  of  the  embryo,  and  may  have  been  originally 
formed  in  consequence  of  those  next  to  the  uterus  laying  hold  by  a 
species  of  animal  attraction  of  the  coagulable  lymph  which  lines 
the  uterus.  It  might  take  place  in  a manner  resembling  what  hap- 
pens when  the  root  of  a plant  spreads  on  the  surface  of  moist  bodies, 
with  this  difference,  that  in  the  present  instance  the  vessels  form  the 
substance  through  which  they  ramify,  as  in  the  case  of  granulations. 

At  the  time,  or  perhaps  before,  the  female  seed  enters  the  uterus, 
coagulable  lymph,  from  the  blood  of  the  mother,  is  thrown  out  every- 
where on  its  inner  surface,  either  from  the  stimulus  of  impregnation 
taking  place  in  the  ovarium,  or  in  consequence  of  the  seed  being  ex- 
pelled from  it.  But  I think  the  first  the  most  probable  supposition; 
for  we  find  in  extra-uterine  cases  that. the  decidua  is  formed  in  the 
uterus,  although  the  ovum  never  enters  it,  which  is  a proof  that  it  is 
produced  by  the  stimulus  of  impregnation  in  the  ovarium,  and  that 
it  is  prior  to  the  entrance  of  the  ovum  into  the  uterus.  When  it  has 
entered  the  uterus  it  attaches  itself  to  that  coagulable  lymph,  by 
which,  being  covered  and  immediately  surrounded,f  there  is  formed 
a soft  pulpy  membrane,  the  decidua,  which  I believe  is  peculiar  to 

* These  quotations  were  taken  from  Mr.  Galhie’s  MS.  of  Dr.  Hunter’s  lectures, 
who  is  one  of  the  gentlemen  that  favoured  Dr.  Hunter,  upon  a former  occasion, 
with  the  use  of  his  notes.  See  Dr.  Hunter’s  Commentaries. 

t This  is  somewhat  similar  to  another  operation  in  the  animal  oeconomy.  If  an 
extraneous  living  part  is  introduced  into  any  cavity  it  will  be  immediately  in- 
closed with  coagulable  lymph.  Thus  we  find  worms  inclosed,  and  hydatids, 
that  have  been  detached,  afterwards  inclosed  ; but  in  those  cases  this  is  a con- 
sequence of  the  pressure  of  the  extraneous  body,  whereas  in  the  uterus  it  is  pre- 
paratory. 


98 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


the  human  species  and  to  monkeys,  I never  having  found  it  in  any 
other  animal.  That  part  which  covers  the  seed  or  foetus,  where 
it  is  not  immediately  attached  to  the  uterus,  and  likewise  forms  a 
membrane,  was  discovered  by  Dr.  Hunter,  and  is  by  him  called 
decidua  reflexa.*  The  whole  of  this  coagulable  lymph  continues 
to  be  a living  part  for  the  time ; the  vessels  of  the  uterus  ramify 
upon  it ; and  where  the  vessels  of  the  foetus  form  the  placenta 
there  the  vessels  of  the  uterus,  after  passing  through  the  decidua, 
open  into  the  cellular  substance  of  the  placenta,  as  before  described. 
As  this  membrane  lines  the  uterus  and  covers  the  seed,  it  is 
stretched  out,  and  becomes  thinner  and  thinner,  as  the  uterus  is 
distended  by  the  foetus  growing  larger,  especially  that  part  of  it, 
called  decidua  reflexa,  which  covers-the  foetus;  as  there  it  cannot 
possibly  acquire  any  new  matter,  except  we  could  suppose  that 
the  fmtus  assisted  in  the  formation  of  it.  This  membrane  is  most 
distinct  where  it  covers  the  chorion ; for  where  it  covers  the 
placenta  it  is  blended  with  coagula  in  the  great  veins  that  pass 
obliquely^  through  it,  more  especially  all  round  the  edge,  where 
innumerable  large  veins  come  out;  but  the  chorion  and  decidua 
can  be  easily  distinguished  from  one  another,  the  decidua  being 
less  elastic. 

From  the  description  now'  given,  I think  w'e  are  justified  in  sup- 
posing the  placenta  to  be  formed  entirely  by  the  foetus,  which  is 
further  confirmed  by  extra-uterine  cases,  and  by  the  formation  of 
the  membrane  in  the  egg,  there  being  no  living  organic  part  to  fur- 
nish them;  and  the  decidua  we  must  suppose  to  be  a production  of 
the  mother:  of  both  which  the  circumstance  of  the  decidua  passing 
between  the  placenta  and  uterus  may  be  considered  as  an  addi- 
tional proof.'  For  if  the  vessels  of  the  fetus  branched  into  a part 
of  the  decidua,  we  might  conceive  the  whole  placenta  to  be  formed 
from  that  exudation ; the  portion  of  it,  where  the  vessels  had  rami- 
fied like  the  roots  of  a plant,,  becoming  thicker  than  the  rest,  and 
forming  the  placenta.  If  that  were  the  case,  this  membrana 
decidua,  when  traced  from  the  parts  distinct,  and  at  a distance  from 
the  placenta,  should  be  plainly  seen  passing  into  its  substance  all 
round  at  the  edges,  as  a continuation  of  it.  But  the  fact  is  quite 
otherwise  ; for  the  decidua  can  be  distinctly  traced  between  the 
placenta  and  uterus,' hardly  ever  passing  between  the  lobuli,  the 
vessels  of  the  foetus  never  entering  into  it,  and  of  course  none  of 
them  ever  coming  in  absolute  contact  with  the  uterus.  But  what 
may  be  considered  as  still  a stronger  proof  that  the  decidua  is  fur- 
nished by  the  uterus  is,  that  in  cases  of  extra-uterine  conception, 
where  the  foetus  is  wholly  in  the  ovarium  or  Fallopian  tube,  we 
find  the  uterus  lined  with  the  decidua,  having  taken  on  the  uterine 

* The  placenta  is  certainly  a foetal  part,  and  is  formed  on  the  inside  of  the 
spongy  chorion,  or  decjdua.  How  far  the  decidua  reflexa  is  a uterine  part  I do 
not  yet  know  ; if  it  is,  tlien  the  ovum  must  be  placed  in  a doubling  of  the  coagu- 
lum,  which  forms  the  decidua;  but  if  the  ovum  is  attached  to  the  inside  of  the 
decidua,  then  the  decidua  reflexa  is  belonging  to  the  foetus. 


ON  THE  STRUCTURE  OF  THE  PLACENTA. 


99 


action ; but  no  placenta,  that  being  formed  by  the  fetus,  and  there- 
fore in  the  part  which  contained  it. 

The  vessels  of  the  foetus  adhering,  by  the  intervention  of  the 
decidua,  to  a certain  portion  of  the  uterus  when  both  are  yet  small,  as 
the  uterus  increases  in  every  part  of  its  surface  during  the  time  of 
uterine  gestation,  we  must  suppose  that  this  surface  of  adhesion 
increases  also ; and  that  by  the  elongation  of  those  vessels  of  the 
fetus  in  every  direction  this  substance  should  likewise  be  increased 
in  every  direction.  This  is  in  some  degree  the  case,  yet  the 
placenta  do.es  not  occupy  so  much  of  the  enlarged  surface  of  the 
uterus  as  one  at  first  would  expect. 

The  vessels  of  the  uterus  in  the  time  of  the  gestation  are  in- 
creased in  size  nearly  in  a proportion  equal  to  the  increased  cir- 
cumference of  the  uterus,  and  consequently  in  a proportion  much 
greater  than  the  real  increase  of  its  substance.  But  when  we  reflect 
that  the  uterus  ought  not  to  be  considered  as  hollow,  but  as  a body 
nearly  solid,  on  account  of  its  contents,  which  derive  support  from 
this  source,  and  that  a much  greater  quantity  of  blood  must  neces- 
sarily pass  than  what  is  required  for  the  support  of  the  viscus  itself, 
we  cannot  be  at  a loss  to  account  for  the  greatly  increased  size  of 
its  vessels. 

The  arteries  which  are  not  immediately  employed  in  conveying 
nourishment  to  the  uterus  go  on  towards  the  placenta,  and,  pro- 
ceeding obliquely  between  it  and  the  uterus,  passthrough  the  decidua 
without  ramifying;  just  before  they  enter  the  placenta,  after 
making  two  or  three  close  spiral  turns  upon  themselves,  they  open 
at  once  into  its  spongy  substance  without  any  diminution  of  size, 
and  without  passing  beyond  the  surface,  as  above  described. 
The  intention  of  these  spiral  turns  would  appear  to  be  that  of 
diminishing  the  force  of  the  circulation  in  the  vessels  as  they  ap- 
proach the  spongy  substance  of  the  placenta,  and  is.  a mechanism 
calculated  to  lessen  the  quick  motion  of  the  blood  in  a part  where 
a quick  motion  was  not  required.  These  curling  arteries  at  this 
temination  are  in  general  about  half  the  size  of  a crow’s  quill,  and 
sometimes  larger. 

The  veins  of  the  uterus  appropriated  to  bring  back  the  blood 
from  the  placenta  commence  from  this  spongy  substance  by  such 
wide  beginnings  as  are  more  than  equal  to  the  size  of  the  veins 
themselves.  These  veins  pass  obliquely  through  the  decidua  to  the 
uterus,  enters  its  substance  obliquely,  and  immediately  communicate 
with  the  proper  veins  of  the  uterus.  The  area  of  these  veins  bears 
no  proportion  to  their  circumference,  the  veins  being  very  much 
flattened. 

This  structure  of  parts  points  out  at  once  the  nature  of  the  blood’s 
motion  in  the  placenta ; but  as  this  is  a fact  but  lately  ascertained, 
a just  idea  may  perhaps  be  conveyed  by  saying  that  it  is  similar,  as 
far  as  we  yet 'know,  to  the  blood’s  motion  through  the  cavernous 
substance  of  the  penis. 

The  blood,  detached  from  the  common  circulation  of  the  mother. 


100 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


moves  through  the  placenta  of  the  fcetus ; and  is  then  returned 
back  into  the  course  of  the  circulation  of  the  mother,  to  pass  on  to 
the  heart. 

This  structure  of  the  placenta,  and  its  communication  with  the 
uterus,  leads  us  a step  further  in  our  knowledge  of  the  connexion 
between  the  mother  and  the  foetus.  The  blood  of  the  mother  must 
pass  freely  into  the  substance  of  the  placenta,  and  the  placenta  most 
probably  will  be  constantly  filled  ; the  turgidity  of  which  will  assist 
to  squeeze  the  blood  into  the  mouths  of  the  veins  of  the  uterus, 
that  it  may  again  pass  into  the  common  circulation  of  the  mother; 
and  as  the  interstices  of  the  placenta  are  of  much  greater  extent 
than  the  arteries  which  convey  the  blood,  the  motion  of  the  blood 
in  that  part  must  be  so  much  diminished  as  almost  to  approach  to 
stagnation.  So  far  and  no  further  does  the  mother  appear  to  be 
concerned  in  this  connexion. 

The  foetus  has  a communication  with  the  placenta  of  another 
kind.  The  arteries  from  the  foetus  pass  out  to  a considerable 
length,  under  the  name  of  the  umbilical  arteries,  and  when  they 
arrive  at  the  placenta  ramify  upon  its  surface,  sending  into  its  sub- 
stance branches  which  pass  through  it,  and  divide  into  smaller  and 
smaller,  till  at  last  they  terminate  in  veins;  these,  uniting,  become 
larger  and  larger,  and  end  in  one,  which  at  last  communicates  w'ith 
the  proper  circulation  of  the  foetus. 

This  course  of  vessels,  and  the  blood’s  motion  in  them,  is  similar 
to  the  course  of  the  vessels  and  the  motion  of  the  blood  in  other 
parts  of  the  body.’' 

[It  is  well  known  that  the  accuracy  of  this  description  has  been  disputed  by 
several  continental  anatomists,  and  has  especially  been  called  in  question  in  this 
country  by  Dr.  Robert  Lee,  F.R.S.,  who,  with  a zeal  becominor  a sincere  lover 
of  truth,  deemed  it  his  duty  to  submit  to  the  scientific  world  the  results  of  a series 
of  investigations,  which  he  considered  to  be  irreconcileable  in  some  respects  with 
the  Hunterian  descriptions.  During  the  period  in  which  Dr.  Lee  was  examining, 
at  the  College  of  Surgeons,  the  Hunterian  Preparations,  illustrative  of  the  struc- 
ture and  connexions  of  the  placenta,  his  observations  on  the  obscurity  produced 
by  apparently  extravasated  injection,  led  me  to  think  .of  some  less  objectionable 
mode  of  demonstrating  the  vascular  communication  between  the  uterus  and 
placenta,  if  it  existed  ; or  of  proving,  more  satisfactorily  than  the  appearance 
pointed  out  by  him  in  the  Hunterian  preparations  seemed  to  do,  that  there  was 
no  such  communication. 

This  I proposed  to  do  by  dissecting  the  parts  under  water  before  disturbing 
them,  either  by  throwing  forcibly  foreign  matter  into  the  vessels,  or  by  separating 
the  placenta  from  the  uterus,  to  observe  the  appearances  presented  by  the  op- 
posed surfaces;  a proceeding  which,  if  done  in  the  air,  is  liable  to  the  objection 
of  the  possibility  of  having  torn  the  vessels  which  were  passing  across,  and  the 
coats  of  which  are  acknowledged  to  be  extremely  delicate. 

For  this  purpose  I was  furnished  by  Dr.  Lee  with  sections  of  an  uninjected  and 
naturally  connected  uterus  and  placenta,  at  the  sixth  month  of  uterine  gestation, 
which  I fixed  under  water  in  an  apparatus  used  for  dissecting  mollusca,  and  com- 
menced the  dissection  from  the  outside,  removing  successively,  and  with  great  care, 
the  layers  of  fibres,  and  tracing  the  veins  as  they  passed  deeper  and  deeper  in 
the  substance  of  the  uterus  in  their  course  to  the  deciduous  membrane ; in  which 
situation,  as  the  thinnest  pellicle  of  membrane  is  rendered  distinct  by  being  sup- 
ported in  the  ambient  fluid,  I naturally  expected  to  see  the  coats  of  the  veins 


ON  THE  STRUCTURE  OF  THE  PLACENTA. 


101 


In. addition  to  what  I have  said  about  the  connexion  between  the 
mother  and  child  in  natural  cases,  it  is  necessary  to  observe,  that 

continued  into  the  deciduous  membrane  and  placenta,  and  to  be  able  to  preserve 
the  appearance  in  a preparation,  if  it  actually  existed  in  nature.  Every  vein, 
however,  when  traced  to  the  inner  surface  of  the  uterus,  appeared  to  terminate  in 
an  open  mouth  on  that  aspect ; the  peripheral  portion  of  the  coat  of  the  vein,  or 
that  next  the  uterus,  ending  in  a well-defined  and  smooth  semicircular  margin, 
the  central  part  adhering  to,  and  being  continuous  with,  the  decidua. 

In  the  course  of  this  dissection  1 observed  that  where  the  veins  of  different 
planes  communicated  with  each  other,  in  the  substance  of  the  walls  of  the  uterus, 
the  central  portion  of  the  parietes  of  the  superficial  vein  invariably  projected  in  a 
semilunar  form  into  the  deeper-seated  one  ; and  where  (as  was  frequently  the 
case,  and  especially  at  the  point  of  termination  on  the  inner  surface),  two,  or 
even  three,  of  these  wide  venous  channels  communicated  with  a deeper  sinus  at 
the  same  jroint,  the  semilunar  edges  decussated  each  other  so  as  to  allow  only 
a very  small  part  of  the  deep-seated  vein  to  be  seen.  It  need  scarcely  be  ob- 
served how  admirably  this  structure  is  adapted  to  insure  the  arrest  of  the  current 
of  blood  through  these  passages,  upon  the  contraction  of  the  muscular  fibres 
with  which  they  are  everywhere  immediately  surrounded. 

On  another  portion  of  the  same  uterus  and  placenta,  I commenced  the  exami- 
nation under  water  by  turning  off  the  placenta  and  deciduous  membrane  from  the 
inner  surface  of  the  uterus.  In  this  way  the  small  tortuous  uterine  arteries  which 
enter  the  deciduous  membrane  were  readily  distinguishable,  though  not  filled 
with  injected  matter  ; and,  as  it  was  an  object  to  avoid  unnecessary  force  in  the 
process  of  separation,  they  were  cut  through,  though  they  are  easily  torn  from 
the  decidua.  Hut  with  respect  to  the  veins,  they  invariably  presented  the  same 
appearances  as  were  noticed  in  the  first  dissection,  terminating  in  open  semicir- 
cular orifices,  which  are  closed  by  the  apposition  of  the  deciduous  membrane 
and  placenta.  This  membrane  is,  however,  thinner  opposite  these  orifices  than 
elsewhere,  and  in  tome  places  appeared  to  be  or,  adhering  . to  the  vein, 

was  torn  up  with  it ; but  in  these  cases  the  minute  vessels  of  the  placenta  only 
appeared,  and  never  any  indication  of  a vascular  trunk  or  cell  commensurate 
with  the  size  of  the  vein  whose  terminal  aperture  had  been  lifted  up  from  the  part. 

The  above  results  of  my  examination  of  the  impregnated  uterus,  which  had 
been  furnished. to  me  by  Dr,  Lee,  I communicated,  as  I had  promised  to  do,  to 
that  gentleman.  They  appeared  decisive  of  the  fact  that  the  veins  of  the  uterus 
were  not  continued  as  such  across  the  decidua,  to  terminate  in  visible  cells  in  the 
substance  of  the  placenta  ; but  whether  the  terminal  orfices  of  the  veins  derived 
no  returning  blood  from  the  interstices  of  the  decidual  lamina:,  was  by  no  means 
certain.  For  m3'  own  part,  having  satisfied  myself  of  the  passage  of  the  tortuous 
uterine  arteries  into  the  decidua,  I undoubtedly  considered  the  uterine  venous 
sinuses  as  the  most  probable  and  natural  channels  by  which  the  blood  conveyed 
from  the  uterus  by  the  tortuous  arteries  would  return  again  to  that  body  ; although 
I was  unable  to  determine  from  this  dissection  how  the  blood  was  returned  into 
the  open  mouths  of  the  veins. 

It  must  be  admitted,  that  an  impregnated  uterus  at  the  fifth  month,  where  the 
vessels,  which  are  very  small,  had  been  contracted  by  the  spirit  in  which  the 
parts  had  been  preserved,  was  not  a very  favourable  subject  for  so  delicate  an 
investigation  ; and  I accordingly  felt  extremely  desirous  of  repeating  the  dissec- 
tions on  gravid  uteri  at  a more  advanced  period.  These  opportunities  do  not,  as 
is  well  known,  frequently  occur:  about  a year  after  I was,  however,  favoured  by 
Dr.  Lee  with  a large  portion  of  a gravid  uterus  of  a woman  who  died  about  the 
ninth  month  of  gestation,  in  which  the  uterine  veins  had  been  gently  filled  with  red 
size  injection.  This  preparation  was  submitted  to  the  same  mode  of  dissection.  In 
tracing  those  veins  which  passed  to  the  inner  surface  of  the  uterus,  near  the 
middle  of  the  placenta,  the  injection  was  seen  to  be  continued  from  them  into 
oblique,  wide,  but  shallow  channels,  leading  through  the  external  decidua  into 
the  placental  decidua,  and  had  thence  been  diffused  through  the  fine  spono-j' 

JO* 


102 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


though  the  uterus  is  appropriated  for  the  support  of  the  foetus,  as 
best  fitted  for  that  purpose,  yet  it  is  not  essential  to  its  growth ; as 
any  other  part  in  which  the  child  may  be  situated,  is  capable  of 
receiving  the  same  provisionary  stimulus  for  supplying  it  with 
nourishment  as  the  nterus  ; and  this,  I believe,  is  peculiar  to  genera- 
tion. This  prompts  me  to  make  the  following  observations  upon 
the  diflerent  situations  of  the  foetus  in  extra-uterine  cases,  which 
are  extraordinary,  happen  seldom,  and  when  they  do  occur  are 
often  attended  with  so  many  hindrances  to  critical  investigation,  as 
hardly  to  allow  of  thorough  or  satisfactory  information. 

Such  cases  are  readily  distinguished  from  natural  ones  by  the 
uterus  being  found  entire  and  empty  ; and  they  may  be  divided  into 
three  diflerent  kinds,  according  to  the  situation  of  the  foetus  in  the 
ovarium.  Fallopian  tube,  or  in  the  cavity  of  the  abdomen. 

From  a want  of  the  appearances  which  usually  attend  the  natural 
process,  the  investigation  of  extra-uterine  cases  is  attended  with 
considerable  difficulty.  Fof  wdiere  uncommon  actions  have  taken 
])lace,  as  w'ell  as  in  cases  of  disease,  the  natural  texture  of  the  parts 

cellular  tissue  which  everywhere  surrounds  and  supports  the  fcctal  capillaries. 
On  comparing  these  appearances  witli  iny  first  dissection,  1 perceived  that  the 
uterine  vein,  opposite  the  mouth  of  which  I had  supposed  the  decidua  to  be  want- 
ing, and  whose  orifice  was  in  contact  with  the  capillaries  of  the  placenta,  was 
in  reality  one  of  the  oblique  decidual  canals,  returning  the  blood  from  the  cellular 
substance  of  the  placenta  into  the  uterine  vein,  its  continuity  with  which  had 
been  preserved. 

The  continuation  of  the  uterine  veins  into  decidual  canals  was  much  more  dis- 
tinct in  those  which  terminated  near  the  circumference  of  the  placenta  ; and  here 
the  irregular  portions  of  injection,  which  filled  the  canals  as  far  as  the  surface  of 
the  placenta,  were  evidently  circumscribed,  by  distinct  parietes,  and  not  the 
result  of  confused  extravasation;  the  injection  from  the  decidual  canals  had 
passed  into  the  large  interlobular  Sjiaces,  or  maternal  sinuses  of  the  placenta,  and 
thence  had  become  diffused,  generally  for  the  extent  of  an  inch,  into  the  spongy 
or  cellular  texture  of  the  placenta. 

The  uterine  arteries  in  this  case  had  not  been  injected,  but  were  easily  trace- 
able passing  through  the  external  and  placental  decidua,  as  far  as  the  internal 
surface  of  the  latter,  and  apparently  opening  or  being  lost  on  the  spongy  surface 
of  the  placenta. 

With  reference  to  preparations  of  vascular  and  cellular  structures  like  the  pla- 
centa, it  is  not  easy  to  enforce  conviction  from  the  appearances  they  present,  in 
consequence  of  the  difficulty  of  distinguishing  between  natural  and  accidental 
extravasation. 

Having,  however,  carefully  compared  the  Hunterian  preparations  with  the 
results  of  my  own  examinations  of  the  gravid  uterus  at  the  full  period,  1 now 
believe  they  all  fully  bear  out  Mr.  Hunter’s  general  view,  viz.,  that  the  maternal 
blood  is  diffused,  by  means  of  the  tortuous  arteries,  into  the  spongy  cellular  sub- 
, stance  of  the  placenta,  where  it  bathes  the  capillaries  of  the  fatal  circulation, 
and  is  returned  by  the  oblique  decidual  adventitious  sinuses  and  channels  into 
the  orifices  of  the  uterine  veins.  Thus  the  placental  intercommunication  between 
the  feetus  and  mother,  in  the  human  subject  and  Quadrumana,  is  carried  on  by 
the  contact  of  the  foetal  capillaries  with  maternal  extravasated  blood  ; while  in 
the  Ruminants,  the  mare,  and  the  sow,“  it  takes  place  by  the  apposition  ofcapillaries 
to  capillaries,  and  the  two  parts  of  the  placenta,  viz.,  foetal  and  maternal,  can  be 
separated.  In  the  Ferae  and  Rodentia  there  appears  to  bean  intermediate  structure.] 


“ [In  the  last  two  examples  the  placenta  may  be  said  to  be  diffused  over  nearly 
th  ewhole  surface  of  the  chorion.] 


ON  THE  PLACENTA  OF  THE  MONKEY. 


103 


is  very  much  altered,  and  appears  to  be  lost,  not  only  by  the  parts 
themselves  being  enlarged,  but  from  having  a great  deal  of  new 
matter  superadded  to  them,  by  which  they  lose  their  natural  dis- 
tinctness, and  become  less  fitted  for  examination  than  those  which 
only  have  a relation  to  them,  and  which  preserve  their  natural 
actions  peculiar  to  that  state. 

From  these  difficulties,  and  a want  of  accuracy  in  those  who 
made  the  examination,  it  is  not  at  present  clear,  with  respect  to 
many  of  the  extra-uterine  cases  upon  record,  whether  they  were 
ovarian  cases.  Fallopian  tube  cases,  or  abdominal  cases;  when,  if 
they  had  been  acquainted  with  the  principle  in  which  they  differ, 
nothing  could  have  been  more  easy  than  to  distinguish  them.  It  is 
not  difficult,  perhaps,  at  the  very  first  view,  to  distinguish  an  abdo- 
minal case  from  either  of  the  two  first ; for  if  the  ovariaand  Fallo- 
pian tube  are  entire,  naitural,  and  can  be  well  distinguished  to  be 
as  those  parts  are  when  the  circumstances  are  natural.,  then  we 
may  be  sure  it  is  an  abdominal  case.-  Appearances,  however,  may 
not  in  all  cases  be  distinct ; but  the  parts  may  adhere,  or  be  other- 
wise rendered  so  obscure,  that  an  abdominal  case  might  be  con- 
founded with  either  of  the  two  first ; therefore  it  is  essential  to  have 
a characteristic  difference  established  between  the  two  first,  and 
the  third. 

The  invariable  differeace  between  the  two  first,  and  the  abdominal 
cases,  will  be  in  the  vessels  by  which  the  child  is  nourished  : for 
the  arteries  and  veins  belonging  to  the  part  in  which  the  child  is 
contained  must  be  enlarged  ; which,  being  the  increase  of  a natural 
part,  will  be  readily  ascertained,  and  the  nature  of  the  case  as 
readily  determined.  W e may  lay  it  down  as  a principle,  that  when 
the  spermatic  artery  and  veins  of  either  side  are  enlarged  in  an 
extra-uterine  case,  that  the  foetus  is  in  the  ovarium  or  Fallopian 
tube;  since  there  are  no  other  blood-vessels  which  supply  these 
parts ; and  if  any  other  system  of  vessels,  as  the  mesenteric,  are 
increased  in  size,  while  the  spermatic  are  in  a natural  state,  v/e 
may  with  equal  certainty  conclude  the  foetus  to  be  contained  in  the 
general  cavity  of  the  belly.  As  this  becomes  the  great  criterion, 
and  as  the  situation  and  time  will  not  always  allo\y  very  nice  in- 
vestigation on  the  spot,  where  the  person  employed  has  an  oppor- 
tunity of  taking  away  the  parts  concerned,  I would  advise  his  taking 
along  with  them  the  aorta  and  vena  cava,  cut  through  above  the 
origins  of  the  spermatic  vessels. 


8.  OBSERVATIONS  ON  THE  PLACENTA  OF  THE 

MONKEY. 

Moxkeys  always  copulate  backwards : this  is  performed  some- 
times when  the  female  is  standing  on  all-fours ; and  at  other  times 
the  male  brings  her  between  his  thighs  when  he  is  sitting,  holding 
her  with  his  fore  paw's. 


104 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  female  has  her  regular  periods  for  the  male,  but  she  has 
commonly  too  much  complaisance  ever  to  refuse  him.  They  carry 
this  still  further,  for  they  receive  the  male  when  with  young,  even 
when  pretty  far  gone  : at  least  this  was  the  case  with  one  of  which 
I am  going  to  give  an  account. 

A female  monkey,  belonging  to  Mr.  Endersbay,  in  the  summer 
1782,  had  frequently  taken  the  male.  The  keeper  observed  that 
after  the  21st  of  June  she  became  less  lively  than  usual,  although 
it  was  not  suspected  that  she  had  conceived but  some  time  after 
appearing  to  be  bigger  in  the  belly,  it  created  a suspicion  of  her 
being  with  young.  Great  attention  was  paid  to  her,  and  great  care 
W'as  taken  of  her.  She  went  on  gradually  increasing  in  size  ; and 
at  last  something  was  observed  to  move  in  her  belly  at  particular 
times,  and  the  motion  could  even  be  felt  through  the  abdominal 
muscles.  She  became  indolent,  and  did  not  like  to  leap  or  perform  her 
usual  feats  of  activity.  Towards  the  latter  part  of  the  time  they 
perceived  the  breast  and  nipple  to  have  become  rather  fuller,  and 
that  a kind  of  water  could  be  squeezed  out  at  the  nipple.  Some 
time  before  she  brought  forth,  she  became  red  about  the  hips  and 
posteriors,  which  redness  extended  to  the  inside  of  the  thighs.  It 
being  now  certain  that  she  w'as  with  young,  I desired  that  she 
might  be  particularly  attended  to  when  there  were  signs  of  ap- 
proaching delivery,  both  on  her  owm  account  and  that  of  the  young 
one,  and  requested  the  afterbirth  might  be  carefully  preserved,  as 
that  part  would  assist  to  ascertain  the  mode  of  uterine  gestation. 
These  directions  were  attentively  followed;  and  when  in  labour  it 
W’as  observed  that  she  had  regular  pains,  that  when  the  young  one 
was  in  part  come  into  the  world,  she  assisted  herself  w'ith  her  fore 
paws,  and  that  it  came  with  the  hind  parts  first.  This  happened 
on  the  15th  of  December  1782, -in  all  about  six  months  after  con- 
ception ; and  when  she  brought  forth  her  young  one  it  showed 
signs  of  life,  but  died  immediately,  owfing  probably  to  the  unfavour- 
able mode  of  its  being  brought  into  the  world.  When  delivered  she 
took  the  young  one  up,  and  although  it  was  dead  clasped  it  to 
her  breast. 

The  iifterbirth  w'as  preserved  entire,  and  was  perfectly  fit  for 
examination.  It  consisted  of  placenta,  with  the  membranes  and 
navel-string,  which  all  very  much  resembled  the  corresponding 
parts  in  the  human  subject,  as  will  now  be  described.  j 

The  placenta  had  the  appearance  of  being  divided  into  tw’o 
oblong  bodies,  united  by  their  edges,  each  terminating  in  an  obtuse 
point  at  the  other  end,  which  were  of  course  at  some  little  distance 
from  one  another. 

It  is  probable  that  these  two  points  were  placed  towards  the 
openings  of  the  Fallopian  tubes,  where  the  uterus  assumes  a form 
resembling  two  obtuse  horns. 

The  two  lobes  above-mentioned  wmre  made  up  of  smaller  ones, 
united  closely  at  their  edges,  wdiich,  were  more  apparent  and  dis- 
tinct at  some  parts  than  at  others.  Some  of  these  lobes  were 
divided  by  fissures  w'hich  seem  to  be  derived  from  one  centre,  while 


OF  A WOMAN  WHO  HAD  THE  SMALL-POX,  ETC.  105 

there  were  others  near  the  edges  passing  in  a*  different  direction, 
in  which  fissures  are  placed  veins  or  sinuses  that  receive  the  blood 
laterally  from  the  lobes.  The  substance  of  the  placenta  seems  to 
be  cellular,  as  in  the  human  subject : this  structure  allows  a com- 
munication to  be  kept  up  between  different  parts  of  each  lobe,  and 
the  sinuses  allowing  of  a communication  between  the  different  lobes 
of  which  the  placenta  is  composed,  the  blood  passes  into  the  fissures 
before  it  enters  the  veins;  in  which  respect  it  differs  from  the 
human  placenta. 

The  arteries  from  the  uterus,  on  the  surface  of  the  placenta, 
were  visible,  but  too  small  to  be  injected:  I cannot  therefore  say 
how  they  terminated  in  the  placenta. 

The  principal  veins  arose  in  general  from  the  fissures  beginning 
from  the  surface,  as  in  the  human  placenta  ; but  besides  these,  there 
were  other  small  ones;  all  which,  we  may  suppose,  pass  through 
the  decidua  and  enter  the  substance  of  the  uterus,  most  probably  in 
the  same  way  as  in  the  human  subject. 

The  membranes  are  the  amnios,  the  chorion,  and  the  membrana 
decidua.  These  appear  to  be  much  the  same  as  in  the  human, 
except  that  the  decidua  is  considerably  thicker,  especially  where  it 
passes  between  the  uterus  and  the  placenta. 

The  navel-string  in  the  monkey  is  not  proportionally  so  long  as 
in  the  human,  and  is  very  much  and  very  regularly  twisted. 

There  is  no  urachus,  and  of  course  no  allantois;  not  even  the 
small  ligament  that  appears  to  be  a drawing-in  of  the  bladder  at  its 
attachment  to  the  navel,  the  bladder  here  being  rounded. 


9.  ACCOUNT  OF  A WOMAN  WHO  HAD  THE  SMALL- 
POX DURING  PREGNANCY,  AND  WHO  SEEMED  TO 
HAVE  COMMUNICATED  THE  SAME  DISEASE  TO 
THE  FCETUS.  BY  JOHN  HUNTER,  ESQ.,  F.R.S.* 

Read  January  17,  1780. 

Mr.  Grant's  Account. 

On  the  5th  of  December,  1776,  Mrs.  Ford  had  been  seized  with 
shivering  and  the  other  common  symptoms  of  fever,  to  which  were 
added  great  difficulty  of  breathing  and  a very  hard  cough.  Mr. 
Grant  saw  her  on  the  7th,  and  he  took  from  her  eight  ounces  of 
blood,  and  gave  her  a composition  of  the  saline  mixture  with  sper- 
maceti and  magnesia  every  six  hours. 

This  had  operated  by  the  8th  two  or  three  times  very  gently, 
when  most  of  the  complaints  were  relieved  ; but  the  cough  still 
shaking  her  violently,  bleeding  seemed  necessary  to  be  repeated, 
more  particularly  as  she  looked  upon  herself  to  be  in  the  sixth 

• [Originally  published  in  the  Philosophical  Transactions,  vol.  Ixx.,  1780.] 


106 


HUNTER  ON  THE  ANIMAL  03C0N0MY. 


month  of  her  pregnancy.  The  medicine  was  continued  without  the 
magnesia. 

In  the  evening  (viz.,  the  8th)  the  small-pox  appeared,  which 
proved  of  a mild  kind,  and  moderate  in  quantity.  Its  progress  was 
rather  slower  than  might  have  been  expected ; but  the  woman 
passed  through  the  disease  in  great  spirits,  sitting  up  the  greatest 
part  of  the  day  during  the  whole  time,  and  taking  only  a paregoric 
at  night,  and,  as  occasion  required,  a little  magnesia;  thus  the 
symptoms  were  mitigated,  and  the  cough  at  last  became  very  little 
troublesome. 

On  the  25th  she  complained  of  a pain  in  her  side.  Eight  ounces 
of  blood  were  taken  away.  The  next  day  she  was  quite  free  from 
pain,  and  thought  herself  as  well  on  the  27th  as  her  particular 
situation  would  admit  of;  after  which  she  was  not  visited  by  Mr. 
Grant  till  the  31st,  when  she  was  in  labour. 

Mr.  WastaWs  Letter  on  the  same  subject. 

December  30,  1776,  I was  sent  for  to  Mrs.  Ford,  a healthy 
woman,  about  twenty-two  years  of  age,  who  was  pregnant  with 
her  first  child.  She  had  come  out  of  the  country  about  three 
months  before.  Soon  after  her  arrival  in  town  she  was  seized  with 
the  small-pox,  and  had  been  under  the  care  of  Messrs.  Hawkins 
and  Grant,  who  have  favoured  me  with  the  particulars  here 
annexed. 

I called  upon  her  in  the  afternoon,  she  complained  of  violent 
griping  pains  in  her  bowels,  darting  down  to  the  pubes.  On  ex- 
amining, I found  the  os  tineas  a little  dilated,  with  other  symptoms 
of  approaching  labour.  I sent  her  an  anodyne  spermaceti  emulsion, 
and  desired  to  be  called  if  her  pains  increased.  I was  sent  for. 
The  labour  advanced  very  slowly  ; her  pains  were  long  and  severe: 
she  was  delivered  of  a dead  child  with  some  difficulty. 

Observing  an  eruption  all  over  the  body  of  the  child,  and  several 
of  the  pustules  filled  with  matter,  I examined  them  more  particu- 
larly; and  recollecting  that  Dr.  Leake,  in  his  Introductory  Lecture 
to  the  Practice  of  Midwifery,  had  observed,  that  it  might  be  neces- 
sary to  inquire-whether  those  adults  who  are  said  totally  to  escape 
the  small-pox  have  not  been  previously  affected  with  it  in  the  womb, 
I sent  a note  to  Dr.  Leake,  and  likewise  to  Dr.  Hunter,  in  hopes  of 
ascertaining  a fact  hitherto  much  doubted.  Dr.  Leake  came  the 
same  evening,  and  saw  the  child.  Dr.  Hunter  came  afterwards, 
with  Mr.  Cruickshank,  and  examined  it ; also  Mr.  John  Hunter  and 
Mr.  Falconer;  who  all  concurred  with  me,  that  the  eruption  on  the 
child  was  the  small-pox.  Dr.  Hunter  thought  the  eruption  so  like 
the  small-pox  that  he  could  hardly  doubt ; but  said,  that  in  all  other 
cases  of  the  same  kind  that  he  had  met  with,  the  child  in  utero  had 
escaped  the  contagion. 


OF  A WOMAN  WHO  HAD  THE  SMALL-POX,  ETC. 


107 


From  Mr.  Grant’s  Notes. 

The  eruption  appeared  on  Mrs.  Ford  in  the  evening  of  the  8th  of 
December,' and  she  was  delivered  the  31st,  that  is,  twenty-three 
days  after  the  appearance  of  the  eruptions. 

Rejlections  hy  Mr.  John  Hunter. 

The  singularity  of  the  above  case,  with  all  its  circumstances,  has 
inclined  me  to  consider  it  with  some  attention. 

There  can  be  no  doubt  that  the  mother  had  the  small-pox,  and 
that  the  eruption  began  to  appear  on  the  8th  of  December;  also, 
that  it  went  through  its  regular  stages,  and  that  on  the  31st,  viz. 
twenty-three  days  after  the  first  appearance  of  the  eruption  the 
woman  was  delivered  of  the  child,  who  is  the  subject  of  this 
paper. 

Secondly,  The  distance  of  time  when  she  had  the  small-pox  before 
delivery,  joined  with  the  stage  of  the  disease  in  the  child  when 
born,  which  probably  was  about  the  sixth  or  seventh  day  of  the 
eruption,  viz.,  about  fifteen  or  sixteen  days  after  the  beginning  of  the 
eruption  on  the  mother,  perfectly  agrees  with  the  possibility  of  the 
infection’s  being  caught  from  the  mother. 

Thirdly,  The  external  appearance  of  the  pustules  in  the  child  was 
perfectly  that  of  the  small-pox,  as  must  have  appeared  from  the 
relation  given  in  Mr.  Wastall’s  letter.  Most  of  the  pustules  were 
distinct,  but  some_were  blended  or  united  at  their  base.  The  face 
had  the  greatest  number,  and  these  were  in  general  the  most  in- 
distinct. They  were  somewhat  flattened,  with  a dent  in  the 
middle.^ 

So  far  were  the  leading  circumstances  and  external  appearances 
in  favour  of  their  being  the  variolous  eruption  ; but  although  these 
leading  circumstances  and  external  appearances  were  incontro- 
vertible, yet  they  were  not  an  absolute  proof  of  this  being  the 
genuine  small-pox;  therefore  I must  be  allowed  to  consider  this 
subject  a little  further,  and  see  how  far  all  the  circumstances  cor- 
respond or  are  similar  to  the  true  small-pox.  In  the  small-pox  we 
have  a previous  fever,  in  place  of  which,  in  the  present  case,  we 
have  no  information  but  that  of  the  mother’s  having  had  the  small- 
pox within  such  a limited  time  as  may  favour  the  possibility  of  in- 
fection in  the  womb  ; yet  we  may  presume  that  the  child  must  have 
had  considerable  fever  preceding  such  an  eruption,  of  whatsoever 
kind  it  was. 

In  the  small-pox  the  eruption  goes  through  pretty  regular  stages  in 
its  progress  and  declension,  which  circumstances  we  know  nothing 
of  in  the  present  case;  but  even  this  fever,  the  eruptions,  and  their 

* I endeavoured  to  take  some  matter  upon  the  point  of  two  lancets ; but  not 
having  an  opportunity  of  making  an  experiment  myself,  I gave  them  to  two  gen- 
tlemen, who,  I imagine,  were  afraid  of  inoculating  with  them. 


lOS 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


progress,  are  not  absolutely  proofs  that  the  disorder  is  the  small-pox 
when  it  is  caught  in  the  common  and  natural  way;  and  in  proof  of 
this  assertion,  it  may  be  observed,  that  practitioners  every  now  and 
then  are  mistaken. 

It  maybe  asked.  What  is  the  true  characteristic  of  the  small-pox? 
That  by  which  it  difiers  from  all  other  eruptions  that  we  are  ac- 
quainted with  ? The  most  certain  character  of  the  small-pox  that 
I know  is,  the  formation  of  a slough,  or  a part  becoming  dead  by 
the  variolous  inflammation  ; a circumstance  which  hitherto,  I be- 
lieve, has  not  been  taken  notice  of. 

This  was  very  evident  in  the  arms  of  those  who  were  inoculated 
in  the  old  way,  where  the  wounds  were  considerable,  and  were 
dressed  every  day;  which  mode  of  treatment  kept  them  from  scab- 
bing, by  which  means  this  process  was  easily  observed  ; but  in  the 
present  method  of  inoculation  it  is  hardly  observable  ; the  sore 
being  allowed  to  scab,  the  slough  and  scab  unite  and  drop  off 
together.  The  same  indistinctness  attends  the  eruptions  on  the 
skin  ; and  in  those  patients  who  die  of,  or  die  while  in,  the  disease, 
where  we  have  an  opportunity  of  examining  them  while  the  part  is 
distinct,  this  slough  is  very  evident. 

This  slough  is  the  cause  of  the  pit  after  all  is  cicatrized  ; for  it 
is  a real  loss  of  substance  of  the  surface  of  the  cutis ; and  in  pro- 
portion to  this  slough  is  the  remaining  depression. 

The  chicken-pox  comes  the  nearest  in  external  appearance  to  the 
small-pox  ; but  it  does  not  commonly  produce  a slough. 

As  there  is  generally  no  loss  of  substance  in  this  case,  there  can 
be  no  pit.  But  it  sometimes  happens,  although  but  rarely,  that 
there  is  a pit  in  consequence  of  chicken-pox  ; then  ulceration  has 
taken  place  on  the  surface  of  the  cutis,  a common  thing  in  sores. 

In  the  present  case,  besides  the  leading  circumstances  mentioned 
in  the  case  of  the  mother,  corresponding  with  the  appearances  on 
the  child,  and  the  external  appearances  themselves,  we  have  in 
the  fullest  sense  the  third  and  real  or  principal  character  of  the 
small-pox,  viz.,  the  slough  in  every  pustule  ; from  all  which,  I think, 
we  may  conclude,  that  the  child  had  caught  the  small-pox  in  the 
womb ; or  at  least  a disease,  the  eifects  of  which  were  similar  to 
no  other  known  disease. 

In  opening  the  bodies  of  those  who  had  either  died  of,  or  died 
while  under,  the  small-pox,  I always  examined  carefully  to  see 
whether  any  internal  cavity,  such  as  the  oesophagus,  trachea, 
stomach,  intestines,  pleura,  peritoneum,  &c.,  had  eruptions  upon 
them  or  not ; and  never  finding  any  in  any  of  those  cavities,  I be- 
gan to  suspect  that  either  the  skin  itself  was  the  only  part  of  the 
body  susceptible  of  such  a stimulus,  or  that  the  skin  was  subject  to 
some  influence  to  which  the  other  parts  of  the  body  were  not  sub- 
ject, and  which  made  it  alone  susceptible  of  the  variolous  stimulus. 
If  from  the  first  cause,  I then  concluded  it  must  be  an  original 
principle  in  the  animal  oeconomy.  If  from  the  second,  I then  sus- 
pected that  external  exposure  was  the  cause ; and  I was  the  more 


OF  A WOMAN  WHO  HAD  THE  SMALL-POX,  ETC, 


ion 


led  into  this  idea,  from  finding  that  these  eruptions  often  attack  the 
mouth  and  throat,  two  exposed  parts ; add  to  which,  that  we  gene- 
rally find  the  eruptions  most  on  the  exposed  parts  of  the  body,  as 
the  face,  &c. 

With  these  ideas  in  my  mind,  I thought  I saw  the  most  favoura- 
ble opportunity  of  clearing  up  this  point.  I therefore  very  attentive- 
ly examined  most  of  the  infernal  cavities  of  this  child ; such  as  the 
peritoneum,  pleura,  trachea,  inside  of  the  oesophagus,  stomach,  in- 
testines, &c.,  but  observed  nothing  uncommon.  J have  already 
observed,  that  in  this  child  the  face  and  extremities  were  the  fullest 
similar  to  what  happens  in  common  : from  all  which  I may  be 
allowed  to  draw  this  conclusion,  that  the  skin  is  the  principal  part 
which  is  susceptible  of  the  variolous  stimulus,  and  is  not  affected 
by  any  externa!  influence  whatever. 

The  communication  of  the  small-pox  to  the  child  in  the  wom.b 
may  be  supposed  to  happen  in  two  ways  ; one  by  infection  from  the 
mother,  as  is  supposed  in  the  above  case ; the  other,  by  the  mother’s 
having  absorbed  the  small-pox  matter  from  some  other  person, 
and  the  matter  being  carried  to  the  child  from  the  connexion 
between  the  two,  which  we  may  suppose  done  with  or  without  first 
affecting  the  mother. 

Testimonies  and  opinions  are  various  with  I'espect  to  these  two 
facts.  Boerhaave  seems  to  have  been  led  by  his  experience  to 
think  that  such  infection  was  not  communicable ; for  we  find 
that  he'  attended  a lady,  who  having,  in  the  sixth  month  of  her 
pregnancy,  had  the  confluent  small-pox,  brought  forth  at  the  regu- 
lar period  a child,  who  showed  not  the  least  vestige  of  his  mother’s 
disease. 

His  commentator,  however,.  Van  Swieten,  supports  a different 
opinion  (see  his  Comment.,  vol.  v.).  He  quotes-  a case  from  the 
Philosophical  Transactions,  vol.  xxviii..  No  337,  p.  165,  of  a woman 
who,  having  just  gone  through  a mild  sort  of  small-pox,  was,  by 
means  of  a strong  dose  of  purging  physic,  thrown  into  a miscarriage, 
and  brought  forth  a dead  female  child,  whose  whole  body  was 
covered  with  variolous  pustules  full  of  ripe  matter:  but  this  history 
is  founded  only  on  the  relation  of  a midwife  to  a clergyman,  and 
therefore  not  absolutely  to  be  depended  upon  as  accurately  stated  ; 
however,  it  is  more  than  probable  that  there  was  a case  as  described, 
and  that  there  w’cre  really  eruptions  on  the  skin  of  the  child  similar 
to  the  small-pox. 

Van  Swieten  likewise  mentions  what  Mauriceau  relates  of  him- 
self. This  author  testifies  that  he  had  often  heard  his  father  and 
mother  say  that  the  latter,  when  big  with  him,  and  very  near  her 
time  of  delivery,  had  a painful  attendance  on  one  of  her  children, 
who  died  of  the  small-pox  on  the  seventh  day  of  the  eruption ; and 
that  on  the  day  followflng  the  death  of  this  child  Mariceau  came  into 
the  world,  bringing  with  him  five  or  six  true  pustules  of  the  small-pox. 

It  does  not  appear,  however,  from  this  recital  whether  or  not 
Mauriceau  passed  through  life  free  from  any  posterior  infection  ; 

11 


110 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


but  admitting  that  this  eruption  of  Mauriceau’s  was  truly  the  small- 
pox, yet  I should  very  much  doubt  his  having  caught  it  from  the 
child  who  died  of  it  ; as  it  should  seem  that  the  pustules  of  Mauri- 
ceau  were  of  the  same  date  with  those  of  the  child  who  died.  Van 
Swieten  appeals  to  a more  recent  case,  which  had  been  reported  to 
him  by  persons  of  great  credit,  and  is  recorded  in  the  Philos. 
Trans,  vol.  xlvi.,  p.  235. 

“ A woman  big  with  child,  having  herself  long  ago  had  the  small- 
pox, very  assiduously  nursed  a maidservant  during  the  w'hole  pro- 
cess of  this  disease.  At  the  proper-  time  she  brought  a healthy 
female  child,  in  whose  skin  Dr.  Watson  asserted  that  he  discovered 
evident  marks  of  the  small-pox,  w'hich  she  must  have  gone  through 
in  the  womb  ; and  the  same  physician  pronounced  that  this  child 
would  be  free  from  future  infection.  After  four  years  her  brother 
was  inoculated  ; and  Watson  obtaitied  permission  of  the  parents  to 
try  the  same  experiment  on  the  girl.  The  operation  was  performed 
bn  both  children  in  the  same  manner,  and  the  pus  used  in  both  cases 
w-as  taken  from  the  same  patient.  The  event,  however,  was  dif- 
ferent: for  the  boy  had  the  regular  eruption,  and  got  well;  but  the 
girl’s  arm  did  not  inflame  nor  suppurate.  On  the  tenth  day  from 
the  insertion  of  the  matter  she  turned  pale  suddenly,  was  languid 
for  two  days,  and  afterwards  w'as  very  well.  In  the  neighbourhood 
of  the  incision  there  appeared  a pustule,  like  those  pustules  that  we 
sometimes  observe  in  persons  who,  having  had  the  disease^  attend 
patients  ill  of  the  small-pox.” 

In  the  Epistles  of  T.  Bartholinus,  Cent.  II.,  p.  682,  there  is  the 
following  history:  “ A poor  woman,  aged  thirty-eight  years,  preg- 
nant, and  now  near  the  time  of  delivery,  was  seized  with  the  symp- 
toms of  the  small-pox,  and  had  a very  numerous  eruption.  In  this 
state  she  -was  delivered  of  a child,  as  full  of  variolous  pustules  as 
herself.  The  child  died  soon  after  birth;  the  mother  three  days 
afterwards.”  Van  Swieten  infers  that  the  mother  and  the  child 
w'ere  in  this  case  iiifected  at  the  same  time  ; therefore,  the  child  not 
infected  by  the  mother. 

Dr.  Mead  asserts  that  when  a woman  in  the  small-pox  suffers  an 
abortion  the  foetus  is  generally  full  of  the  contagion  ; but  that  this 
does  not  happen  always.  This  variety,  he  says,  depends  on  the 
state  of  the-  mother’s  pustules  w'hen^the  child  is  born;  that  is, 
whether  they  are  or  are  not  in  a state  of  purulence.  Whence  he 
ha^  observed  it  sometimes  to  happen  that  on  the  second  day  from 
the  birth,  or  the  third,  or  any  day  before  the  eighth,  the  disease 
caught  from  the  mother  shows  itself  in  eruptions  on  the  child. 

Dr.  Mead  here  relates  the  history  of  a lady  of  quality,  of  which 
this  is  the  substance.  A lady,  in  the  seventh  month  of  her  preg- 
nancy, had  the  confluent  small-pox,  and  on  the  eleventh  day  of  the 
disease  brought  forth  a son,  having  no  signs  of  the  disease  on  his 
body;  and  she  died  on  the  fourteenth  day.  The  infant  having  lived 
four  days,  was  seized  with  convulsions,  and,  the  small-pox  appearing, 
died.  The  doctor  infers  from  hence  that,  the  suppuration  being  in 


OF  A WOMAN  WHO  HAD  THE  SMALL-POX,  ETC. 


Ill 


some  measure  completed  on  the  eleventh  day,  the  mother’s  disease 
M'as  communicated  then  to  the  foetus,  and  made  its  appearance  on 
the  child  after  eight  days. 

If  there  be  no  abortion.  Dr.  Mead  pronounces  that  the  child  will 
ever  be  free  from  the  disease,  unless  the  birth  should  happen  before 
the  maturation  of  the  pustules.  He  brings  a case  to  prove  that  the 
foetus  in  the  womb  may  be  infected  by  the  contagion  of  which  the 
mother  does  not  partake.  “ A woman,  w'ho  had  long  before  suf- 
fered the  small-pox,  nursed  her  husband,  under  that  disease,  towards 
the  end  of  her  pregnancy;  and  was  brought  to  bed  at  the  due 
time.  The  child  was  dead,  and  covered  all  over  with  variolous 
pustules.”  ‘ . 

With  respect  to  the  case  quoted  from  Mauriceau,  it  has  been 
proved  by  Sir  George  Baker  (Med.  Transact.,  vol.  ii.,  p.  275),  that 
Dr.  Mead  drew  a conclusion  from  it  directly  contrary  to  the 
author’s  meaning.  The  negative  opinion  appears  evidently  to  be 
supported  by  that  history.  • 

Sir  George  Baker  mentions  in  the  same  paper  the  case  of  two 
pregnant  women  who  w'ere  inoculated  at  Hertford.  They  both 
had  the  small  pox  favourably,  and  afterwards  brought  forth  their 
children  perfectly  healthy  at  the  usual  time.  Both  these  children, 
at  the  age  of  three  years,  were  inoculated  with  efiect. 

Sir  George  Baker  likewise  mentions  a case  which  fell  under  the 
observation  of  Dr.  Clarke  of  Epsom.  “ A woman  towards  the  end 
of  her  pregnancy  had  the  small-pox,  from  which  she  narrowly 
escaped.  Five  w’eeks  after  the  crisis  she  was  delivered  of  a healthy 
female  child,  who  having  numerous  marks  on  her  skin  was  judged 
by  all  who  saw  her  to  have  undergone  the  same  distemper  before 
her  birth.  However,  at  the  end  of  twelve  months  she  had  the 
small-pox  in  a very  severe  manner.  Both  the  mother  and  child 
were  lately  living  at  Epsom.” 

Since,  then,  we  see  that  it  is  very  probable  that  the  small-pox 
maybe  caught  from  the  mother  when  she,  is  infected,  if  may  be 
asked  why  does  not  this  happen  oftenerl  In  answer  to  this  we  may 
suppose  that  this  is  not  so' ready  a way  as  when  the  child  is  exposed 
to  catch  it  after  the  birth,  as  we  find  too  -that  a difierence  can  be 
produced  after  birth;  viz.,  inoculation  is  a much  readier  way  of 
catching  it  than  what  is  called  the  natural  way.  ' It  may  likewise 
be  said  that  many  Women  who  are  with  child.,  and  have  the  small- 
pox during  pregnancy,  do  not  recover ; therefore  both  mother  and 
child  die  before  the  disease  can  have  time  to  produce  eruptions 
upon  the  child.  Finally,  in  many  of  those  cases  where  the  mother 
recovers,  there  is  sometimes  produced  a miscarriage,  which  also 
hinders  the  infection  from  taking  place  in  the  child-  However, 
many  women  go  through  the  whole  disease,  and  the  child  shows 
no  marks  of  the  small-pox. 

Thus  have  I stated  facts  relative  to  the  present  subject,  with 
some  ot  the  best  authorities  on  both  sides  of  the  question;  and  shall 
now  leave  the  reader  to  form  his  own  judgment. 


112 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


10.  SOME  OBSERVATIONS  ON  DIGESTION. 

The  paper  which  I formerly  presented  to  the  Royal  Society, 
“ On  the  Stomacli  itself  being  digested  after  Death,”  was  published 
in  1772,  in  the  G2d  volume  of  the  Philosophical  Transactions,  and 
has  attracted  the  attention  of  Spallanzani*'  and  others.  In  the 
course  of  these  my  observations  I shall  make  some  remarks  upon 
the  experiments  and  opinions  of  these  gentlemen,  compare  them 
with  those  of  Reaumur, f and,  having  given  some  general  facts  of 
my  own  upon  digestion,  shall  conclude  by  adding  a copy  of  the 
above-mentioned  paper,  with  the  hope  that  others  will  take  up  thei 
subject  in  a more  enlarged  point  of  view,  and  prosecute  an  inquiry 
which  is  of  so  much  consequence  in  the  investigation  of  the  opera- 
tions of  the  animal  ceconomy.,  I cannot  at  present  spare  sufficient 
tinie  to  give  my  opinions  at  large  on  this  subject,  with  all  the  ex- 
periments and.  observations  I have  made  upon  it ; but  as  soon  as  I 
have  leisure  I shall  lay  them  before  the  public. 

To  discover  new  parts  has  been  a principal  object  in  the  re- 
searches of  the  young  or  practical  anatomist ; but  the  connexion, 
arrangement,  mode  of  action,  and  uses  of  the  whole,  or  of  particular 
organs,  have  more  commoidy  been  reserved  for  tbe  consideration 
of  those  whose  views  were  extended  further,  an'd  whose  pow'ers  of 
reasoning  had  been  enlarged  by  habits  of  observation  and  inquiry. 
Curious  and  speculative  men  have  likewise  made  attempts  in  this 
way,  but  often  without  being  sufficiently  acquainted  with  the 
structure  of  the  parts  they  w'ere  about  to  consider,  and  consequently 
ill  informed  respecting  their  relations  and  connexions  with  one 
another.  Not  contented  to  reason  from  those  which  were  most 
obvious,  w'hich  might  have  led  to  useful  knowledge,  they  have  been 
directed  by  what  best  suited  their  fancy,  and  have  principally  at- 
tempted the  most  obscure  and  intricate.  Generation,  or  the  mode 
of  continuing  the  species,  and  digestion,  or  the  means  of  preserv- 
ing the  individual,  have  been  with  them  the  great  objects  of  inquiry  ; 
yet  it  does  not  appear  that  they  have  been  very-successful.  Al- 
though digestion,  as  being  one  of  the  most  important  operations  of 
the  animal  mconomy,  and  most  obvious  in  its  effects,  supplies  a 
number  of  facts  to  assist  in  ascertaining  its  powers,  little  has  been 
hitherto  made  out  towards  investigating  the  various  .circumstances 
under  which  it  is  performed. 

The  mode  of  dividing  the  food  for  the  increase  of  its  surface,  in 
some  animals,  suggested  one  method  of  explaining  the  process  of 

* [Spallanzani’s  observations  on  digestion  appeared  first  in  his  work  called 
Fisica  Animule  e Vegeiahile,  12tno.  1782;  a translation  of  which  was  published 
in  London,  with  the  title  ‘ Dissertations  relative  to  the  Natural  History  of 
Animals  and  Vegetables,’ in  1784.] 

f [“  Sur  la  Digestion  des  Oiseaux,”  Mem  de  I'Jlcad,  des  Sciences de  Paris,  1752, 
pp.  26C — 307,  and  pp.  461 — 495.] 


OBSERVATIONS  ON  DIGESTION. 


113 


digestion  ; and  the  secretion  of  a juice,  which  was  supposed  to  have 
the  power  of  converting  vegetable  and  animal  matter  into  a fluid 
proper  for  the  purposes  of  nutrition,  furnished  amother.  Both  these 
opinions  have  had  their  advocates;  and  while  one  part}^  contended 
for  a mechanical  power,  supposed  to  exist  in  the  gizzard,  the  other 
had  recourse  to  a chemical  power,  and  considered  fermentation  as 
the  great  agent  in  digestion.  They  were,. however,  rather  specula- 
tive philosophers  than  practical  anatomists,  and  have  frequently 
been  misled  with  respect  to  the  very  facts  and  observations  whose 
result  was  to  decide  the  truth  of  their  opinions.  What,  for  instance, 
does  it  explain  in  digestion,  that  the  force  of  the  gizzai’d  of  a turkey 
is  found  equal  to  four  hundred  and  seventy-three  pounds'?  Does  it 
aflbrd  a better  solution  of  our  doubts  than  we  should  derive  from 
determining  the  force  of  the  mill  that  grinds  the  wheat  into  flour  ? 
Or,  on  the  other  hand,  will  the  most  correct  idea  of  fermentation 
enable  us  to  account  for  the  various  plnenomena  in  the  operation  of 
digestion?  But  we  can  have  no  very  high  idea  of  experiments 
made  by  men  who,  for  want  of  anatomical  knowledge,  have  not 
been  able  to  pursue  their  reasoning  beyond  the  simple  experiment 
itself. 

The  great  object  should  have  been  an  endeavour  to  discover  the 
universal  agent  in  digestion ; for  the  digestive  organ  is  evidently 
constructed  in  a different  manner  in  different  animals.  The  me- 
chanical power  for  the  division  of  the  food  is  not  universal  ; and 
those  gentlemen  who  consider  this  power  in  the  gizzard  as  the  im- 
mediate cause  of  digestion,  forgot  that  the  same  effect  was  produced 
in  other  classes  of  animals  with  a different  structure  of  stomach, 
by  means  of  the  grinding  teeth.  Thus,  while  the  gizzard  favoured 
the  theory  of  the  mechanical  reasoner,  that  idea  was  again  destroyed 
by  the  membranous  structure  of  the  stomach  in  many  animals, 
w'hich  equally  supplied  the  chemist  with  arguments  in  favour  of 
the  process,  of  fermentation. 

It  is  more  difficult  than  those  gentlemen  imagine,  to  acquire  on 
this  subject  information  sufficiently  accurate  to  be  able  to  explain  a 
process  so  complicated  as  that  of  digestion.  There  are  in  Nature’s 
operations  always  twp  obvious  extremes;  and  the  mind  of  man 
eagerly  adopts  that  which  accords  with  some  principle  to  which 
he  is  attached,  and  with  which  he  is  best  acquainted,  the  inter- 
mediate connexions  and  gradations,  as  being  less  striking,  not  so 
forcibly  affecting  a superficial  inquirer.  . ^ 

It  happens,  unfortunately,  that  those  who  from  the  nature  of  their 
education  are  best  qualified  to  investigate  the  intricacies,  and  im- 
prove our  knowledge  of  the  animal  ceconomy,  are  compelled  to  get 
their  living  by  the  practice  of  a profession  which  is  constant  em- 
ployment. The  only  educated  men  who  have  leisure  are  those  of 
the  Church,  some  of  whom  we  frequently  find  commencing  philo- 
sophers and  physiologists,  though  they  have  not  had  that  kind  of 
education  which  would  best  direct  their  pursuit.  Experiments,  it 
is  true,  may  be  made  by  men  of  this  description ; but  these  must 

11^ 


114 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


neither  be  much  complicated,  nor  have  any  immediate  relation  to 
those  branches  of  knowledge  with  which  they  have  had  few  oppor- 
tunities of  being  acquainted:  at  best,  they  will  seldom  go  further 
than  to  explain,  a single  fact.  To  look  through  a microscope  and 
examine  the  red  globules  of  blood,  to  view  animalcule,  and  give  a 
candid  account  of  what  they  see,  are  points  on  which  such  inquirers 
may  be  allowed  to  indulge  themselves  ; but  it  is  presumption  in  them 
to  affect  to  reason  of  a science  in  which  they  can  have  but  a very 
superficial  knowledge,  or  to  expect  to  throw  light  on  subjects  that 
they  have  not  taken  the  previous  steps  to  understand.  It  should  be 
remembered  that  nothing  in  Nature  stands  alone;  but  that  every 
art  and  science  has  a relation  to  some  other  art  or  science,  and  that 
it  requires  a knowledge  of  those  others,  as  far  as  this  connexion 
takes  place,  to  enable  us  to  become  perfect  in  that  which  engages 
our  particular  attention. 

These  strictures  are  applicable  to  all  those  who  have  made 
experiments  to  explain  digestion.  The  effect  of  the  mechanical 
powers  being  easily  understood,  those  who  considered  digestion 
mechanically  have  in  general  explained  them  justly  as  far  as  they 
applied  to  the  gizzard ; but  their  reasoning  went  no  further,  and  they 
supposed  these  effects  to  be  digestion.  Those  again  who  took  it 
up  chemically,  being  little  acquainted  with  chemistry  and  totally 
ignorant  of  the  principles  of  the  animal  oeconomy,  have  erroneously 
explained  the  operations  of  the  animal  machine  as  subject  to  the 
laws  of  chemistry. 

The  first  inquirers  into  digestion,  struck  only  by  the  extremes  of 
structure,  the  gizzard,  and  membranous  stomach,  paid  no  regard  to 
the  gradations  leading  from  the  one  to  the  other  ; which,  if  propei'ly 
examined,  w'ould  have  materially  assisted  them  to  explain  the 
functions  of  the  stomach. 

Vallisneri,  considering  the  power  of  the  gizzard  in  one  view  only, 
imagined  it  would  be  as  liable  to  be  afl'ected  by  the  mechanical 
powers  necessary  for  digestion  as  the  grain  which  was  to  be  digest- 
ed ; therefore  supposed  the  existence  of  a solvent.  But  though 
Vallisneri  is  entitled  to  no  merit  from  this  idea,  as  the  premises  are 
false,  yet  this  opinion  of  his  set  Reaumur  to  work,  and  has  been  the 
means  of  bringing  several  curious  facts  to  light.*  The  experiments 
' of  Reaumur  were  first  made  with  a view  to  confute  that  opinion, 

* [In  this  historical  sketch,  so  rare  in  the  writings  of  Hunter,  of  the  opinions 
entertained  by  previous  physiologists  on  the  subject  of,  digestion,  the  suggestion 
by  Tyson  of  the  existence  and  use  of  a solvent  or  corrodent  fluid  ought  to  have 
had  a place.  In  his  Anatomy  of  a Rattlesnake  he  observes,  “The  food,  before 
it  can  prove  aliment,  must  be  comminuted,  and  broken  into  the  smallest  particles  ; 
which  in  these  membranous  stomachs  I can’t  see  how  it  can  be  performed  but 
by  corrosion,  A principal  menstruum  in  doing  this  I take  to  be  that  liquor  which 
is  discharged  by  the  glands  that  are  seated,  in  some,  at  the  beginning  of  the 
throat,  and  are  called  salival  ,■  or  Just  above  the  stomach  or  gizzard  of  birds,  and 
called  the  echinus or  in  others  in  the  stomach  itself,  and  called  the  glandulus 
coat,  and  such  I take  the  inner  coat  of  the  stomach  of  our  rattlesnake  to  be.” — 
Fhilos.  Trans,,  xiii.  1683,  p.  33.] 


OBSERVATIONS  ON  DIGESTION. 


113 


and  therefore  birds  having  gizzards  were  adapted  to  his  purpose. 
In  this  pursuit  he  only  attended  to  such  parts  of  the  experiments  as 
best  accorded  with  his  own  opinion,  yet  carefully  guarded  against 
every  possible  accident  that  might  affect  their  accuracy.  Had 
trituration  been  the  immediate  cause  of  digestion,  his  experiments 
on  the  gizzards  of  birds  were  unnecessary ; since  it  would  have  been 
sufficient  to  have  examined  the  food  after  it  had  been  masticated  by 
the  teeth  of  animals  who  have  grinders,  the  teeth  and  gizzard 
answering  one  and  the  same  purpose.  But  the  circumstance  of 
animals  which  masticate  their  food  in  their  mouth  having  also  a 
stomach,  should  have  taught  that  there  was  something  more  in 
digestion  than  trituration. 

Reaumur’s,  first  experiments  were  made  to  ascertain  the  strength 
of  the  gizzard,  with  its  effects,  to  prove  that  sharp  cutting  sub- 
tances  when  swallowed  in  no  way  injured  its  internal  coat,  and 
that  the  common  food  of  the  bird  was  not  dissolved  when  guarded 
against  its  action.  Yet,  after  all  these  proofs,  he  seems  to  doubt, 
and  says,  “Are  we  to  conclude  that  grinding  alone  is  sufficient  to 
convert  the  grain  and  other  aliment  into  a matter  proper  for  the 
nutrition  of  the  animal,  without  undergoing  any  other  preparation  ? 
Seimral  reasons  seem  to  oppose  this:  trituration  alone  might  reduce 
the  grain  into  a flour;  but  Hour  alone  is  not  chyle.”  “From  the 
smell  of  the  aliment  (taken  from  the  gizzards  of  birds)  are  we  not 
led  to  conclude  that  it  undergoes  a fermentation?  This  smell  may 
be  said  to  arise  from  the  liquor  with  which  the  aliment  is  mixed  ; 
but  is  it  likely  that  juices  do  not  dispose  to  fermentation  substances 
in  which  it  is  so  easily  excited?  Fruit  and  flour,  made  into  a 
paste,  require  little  more  than  heat  to  make  them  ferment.”  From 
these  experiments,  made  with  a view  to  prove  that  digestion  is 
carried  on  by  trituration,  Reaumur  was  led  to  suppose  a solvent. 
But  as  there  are  some  birds  whose  stomachs  do  no  not  seem  suffi- 
ciently strong  to  have  the  power  of  trituration,  he  selected  the 
buzzard  as  being  of  that  kind,  and  the  fittest  for  the  subject  of  his 
experiments,  from  the  circumstance  of  its  throwing  up  whatever  is 
solid  and  indigestible ; therefore,  without  killing  the  bird,  he  could 
know  the  result,  and  repeat  the  experiment  as  often  :is  he  thought 
necessary. 

From  the  stomach  in  the  buzzard  being  incapable  of  trituration, 
he  concluded  that  a solvent  was  necessary  for  digestion;  but,  to 
preclude  all  mechanical  effects  of  the  stomach,  in  his  experiments 
he  employed  tin  tubes  filled  with  meat,  which,  after  the  tubes  had 
remained  twenty-four  hours  in  the  stomach  of  the  buzzard,  w’as 
reduced  to  three-fourths  of  its  size,  was  like  threads,  and  was  neither 
putrid,  sour,  nor  volatile,  but  insipid.  On  this  effect  he  made  his 
remarks,  which  are  Very  pertinent.  In  another  experiment,  which 
was  still  more  accurate  and  conclusive,  he  was  convinced  of  the 
action  of  a sdlvent.  He  then  tried  the  soft  bones  of  young  animals, 
and  found  they  were  digested;  and  that  though  the  hard  bones 
were  not  acted  on  so  readily,  yet,  by  returning  the  same  bones 
several  times  into  the  stomach,  they  were  digested  at  last. 


116 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Reaumur  was  next  anxious  to  know  if  such  birds  as  were 
intended  by  Nature  to  live  upon  meat  could  also  digest  vegetables; 
but  the  result  was  not  so  satisfactory.  He  gave  bread  to  his  buz- 
zard, which  upon  being  returned  had  the  appearance  of  having 
been  chewed.  He  next  trjed  a piece  of  ripe  pear,  after  having 
been  twenty-four  hours  in  the  stomach,  had  lost  some  of  its  weight, 
and  had  the  appearance  of  being  boiled  or.  baked  ; and  thence  he 
concludes  that  its  powers  are  too  weak  to  digest  vegetables  so  as 
to  nourish  the  animal. 

To  ascertain  the  nature  of  the  liquor  which  had  such  powers,  he 
tasted  the  jelly  to  which  the  meat  and  bone  had  been  reduced,  sup-- 
posing  that  it  must  be  well  impregnated  with  this  fluid;  but  he 
could  only  distinguish  a bitter  or  a saltish  taste.  To  have  an 
opportunity  of  more  certainly  determining  the  nature  of  this  solvent, 
he  made  his  buzzard  swallow  small  tubes  filled  with  sponge,  which 
imbibed  fifty  grains  of  this  liquor,  having  the  same  taste  as  the  jelly, 
and  changing  blue  paper  to  a red.  He  tried  the  effects  of  this 
liquor  on  meat  out  of  the  body,  with  cornparative  experiments  in 
water;  and  after  twenty-four  hours  the  meat  in  the  water  was 
become  putrid  ; but  that  in  the  liquor  from  the’stomach  was  only 
softened,  not  dissolved.  To  see  how  far  the  analogy  held  good  in 
membranous  stomachs,  he  gave  two  bones  to  a dog,  which  being 
killed  after  twenty-six  hours,  they  were  found  lessened  in  size,  and 
become  as  soft  as  horn.  He  found  that  the  stomach  of  the  dog  did 
not  alter  the  shape  of  any  of  his  tubes. 

He  conveyed  grass  and  hay,  inclosed  in  tubes,  into  the  stomachs 
of  ruminating  animals,  which  substances  were  not  digested,  but 
appeared  as  if  macerated. 

Let  us  enumerate  the  experiments  and  facts  made  out  by  Reau- 
mur. 

The  gizzard  w'as  not  hurt  by  acting  upon  glass,  which  it  ground 
to  a powder. 

The  stomach  or  gizzard  had  hardly  any  visible  motion.  ‘ 

The  force  of  the  gizzard  was  ascertained. 

The  size  of  the  stones  found  in  the  gizzard  was  in  proportion  to 
the  size  of  the  bird. 

The  stomach  of  a buzzard  digested  bone,  from  which  he  con- 
cluded the  gastric  juice  had  a solvent  power  ; but  it  did  not  digest 
bread,  although  it  acted  in  a slight  degree  on  fruit. 

He  made  experiments  with  the  gastric  juice. 

The  juice  in  the  ruminating  animals’  stomachs  produced  no  effect 
on  hay  or  grass  when  inclosed  in  tubes. 

Reaumur’s  experiments,  although  not  complete,  paved  the  way 
for  future  investigation  ; and  Spallanzani,  proceeding  on  the  same 
ground,  has  not  only  confirmed  them  by  his  own,  but  has  established 
several  points  not  completely  made  out  by  Reaumur;  for  in  some 
instances  Reaumur  gave  up  the  point  too  soon,  especially  in  the 
experiments  respecting  the  buzzard’s  power  of  digesting  vegetables. 
Reaumur  not  possessing  general  knowledge  sufficient  to  direct  him 


OBSERVATIONS  ON  DIGESTION. 


117 


in  his  pursuits,  was  necessarily  confined  to  what  he  was  most 
master  of,  the  mere  making  experiments.  Being  neither  an  anato- 
mist nor  a physiologist,  he  has  not  been  perfectly  just  in  his 
description  of  parts,  having  considered  the  crop  and  the  oesophagus 
leading  from  it  to  the  gizzard  as  two  distinct  stomachs ; but  this, 
however,  is  only  to  be  set  down  as  a piece  of  anatomical  ignorance, 
not  affecting  the  subject  in  the  least.  Spallanzani  is  also  deficient 
in  his  anatomical  knowledge  ; yet  it  must  be  owned  that. his  experi- 
ments, as  far  as  they  go,  are  in  themselves  conclusive ; but  like  all 
mere  experiment-makers,  he  is  not  satisfied  even  with  those  which 
are  clear  and  decisive,  but  multiplies  them  most  unnecessarily, 
without  varying  them  to  elucidate  other  and  essential  parts  of  the 
same  subject,  f think  we  may  set  it  down  as  an  axiom,  that 
experiments  should  not  be  often  repeated  which  tend  merely  to 
establish  a principle  already,  known  and  admitted ; but  that  the 
next  step  should  be,  the  application  of  that  principle  to  useful  pur- 
poses. If  Spallanzani  had  employed  half  his  time  in  this  way,  and 
had  considered  digestion  under  all  the  various  states  of  the  body 
and  stomach,  with  all  the  varieties  of  food,  both  natural  and  artifi- 
cial, he  had  employed  his  time  much  better  than  in  making  experi- 
ments without  end. 

The  food  of  animals  in  general  being  composed  either  of  vege- 
tables, animals,  or  both,  and  a solvent  admitted  as  an  agent  in 
digestion,  it  only  remained  to  prove,  that  the  effect  of  the  process 
of  digestion  was  to  produce  from  these  various  substances  an 
animal  matter,  similar  in  all  animals  who  live  on  such  substances. 
But  the  application  of  principles  requires  more  than  simply  the 
knowledge  of  the  principle  itself,  and  therefore  those  who  cannot 
reason  from  analogy,  or  draw  general  conclusions  from  a few'  con- 
vincing facts,  and  who  require  to  have  every  relative  conclusion  or 
inference  proved  by  an  experiment,  must  be  pleased  with  Spallan- 
zani; but  he  must  tire  even  those  whom  he  informs,  and  much 
more  those  who  read  his  works  in  expectation  of  something  new. 

To  make  comparative  experiments  upon  the  digestive  pow'er,  the 
different  animals  destined  for  that  purpose  should  be  under  similar 
circumstances  as  far  as  relates  to  digestion  ; they  should  be  equal 
in  age,  for  the  growing  eat  more  than  the  full-grown,  and  of  course 
digest  faster;  which  point,  therefore,  can  be  best  ascertained  by 
selecting  those  in  each  class  of  animals  which  have  attained  their 
full  growth.  They  should  be  equal  in  fatness,  for  this  makes  a 
very  material  difference  in  the  pow'ers  of  digestion  in  the  same 
animal;  and  they  should  be  equal  in  health,  a circumstance  which, 
of  all  others,  probably  makes  the  greatest  difference  in  the  powers 
of  the  stomach.  In  comparing  animals  of  the  same  class,  the 
atmosphere  should  likewise  be  of  the  same  temperature ; for  the 
different  classes  of  animals  are  variously  affected  by  the  same 
degree  of  heat.  Experiments  niade  upon  snakes  and  lizards  in  the 
winter  will  differ  greatly  from  those  made  in  the  summer,  while 
similar  experiments  made  on  dogs  will  have  nearly  the  same  result 


118 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


ia  both  seasons.  Nor  will  the  powers  of  the  stomach  be  found 
always  equal  in  the  same  class.  Sleeping  animals  of  the  quadruped 
kind,  as  hedgehogs,  do  not  digest  in  the  winter,  but  in  the  summer 
only  ; therefore  the  conclusions  to  be  drawn  from  experiments  made 
respecting  the  digestive  powers  in  the  one,  are  not  at  all  applicable 
to  those  made  in  the  other  season. 

Spallanzani  observed  that  the  snake  digested  food  faster  in  June, 
when  the  heat  was  at  82°  and  83°,  than  in  April,  when  it  was  only 
60°;  trom  whence  he  concludes,  that  heat  assists  digestion  ; but 
this  heat  is  not  the  immediate,  but  the  remote  cause  of  the  increased 
power;  heat  having  produced  in  the  animal  greater  necessity  for 
nourishment,  and  of  course  greater  powers,  gastric  juice  W'as 
secreted  faster  or  in  greater  quantity. 

As  a proof  that  heat  does  not  act  as  an  immediate,  but  only  as  a 
remote  cause  in  assisting  digestion,  I shall  mention  the  effect  it  pro- 
duced upon  a hedgehog,  the  subject  of  Mr.  Jenner’s  third  experi- 
ment on  the  heat  of  that  animal,  related  in  another  part  of  this 
wmrk. 

“ The  hedgehog,  while  the  heat  of  the  stomach  W'as  at  30°,  had 
neither,  desire  for  food,  nor  power  of  digesting  it;  but  when  in- 
creased by  inflammation  in  the  abdomen  to  93°,  the  animal  seized 
a toad  which  happened  to  be  in  the  room,  and,  upon  being  oflered 
some  bread  and  milk,  it  immediately  ate  it.  The  heat  roused  up 
the  actions  of  the  animal  ceconorny  ; and  the  parts  being  unable  to 
carry  on  these  actions  without  being  supplied  with  nourishment,  the 
stomach  was  stimulated  to  digest,  to  afford  them  that  supply.” 

Spallanzani  also  mentions  the  slowness  of  digestion  in  serpents, 
and  quotes  Bomare,  who  gives  an  account  of  a serpent*at  Martinico, 
in  whose  stomach  a chicken  had  remained  for  three  months  without 
being  completely  digested,  the  feathers  still  adhering  to  the  skin.* 
The  truth  of  this  fact  I should  very  much  doubt,  especially  in  so 
warm  a climate  as  that  of  Martinico,  where  I must  suppose  the 
digestive  powers  to.be  constantly  required;  unless  there  is  in 
Martinico,  as  in  colder  climates,  a torpid  season, f where  the  act 
of  digestion  is  not  necessary  ; but  in  that  case  the  serpent  would 
not  have  swallowed  the  chicken. 

At  Belleisle,  in  the  beginning  of  .the  winter  1761-2,  I conveyed 
worms  and  pieces  of  meat  dowm  the  throats  of  lizards  when  they 
were  going  into  winter  quarters,  keeping  them  afterwards  in  a cool 
place.  On  opening  them  at  different  periods  I always  found  the 
substances  which  1 had  introduced  entire,  and  without  any  altera- 
tion : sometimes  they  were  in  the  stomach  ; at  other  times  they  had 

* Bomare,  Diet,  d'liistoire  Nat. 

f [This  conjecture  is  true;  the  dry  season  in  some  tropical  climes  is  that 
durinnf  w’hich  reptiles  and  insects  retire  to  their  hiding-places  and  become 
torpid  ; they  are  awakened  and  called  into  activity  by  the  showers  of  the  rainy 
season. 

The  tenrec,  a mammiferous  animal  of  Madagascar  and  the  Mauritius,  re- 
sembling the  hedgehog,  also  sleeps  in  a state  of  lethargy  from  April  to  Novem- 
ber, when  the  mean  temperature  exceeds  our  summer  heat.] 


OBSERVATIONS  ON  DIGESTION. 


119 


passed  into  the  intestine;  and  some  of  the  lizards  that  were  pre- 
served alive  voided  them  towards  the  spring,  with  but  very  little 
alteration  in  their  structure.  So  that  digestion  is  regulated  by  the 
other  actions  of  the  body  : warmth  requires  action  suitable  to  that 
warmth;  the  body  requires  nourishment  suitable  to  that  action; 
and  the  stomach  being  called  upon,  performs  the  office  of  digestion. 

Nothing  can  show  more  clearly  that  the  secretion  of  the  gastric 
juice  is  increased  in  proportion  to  the  call  for  nourishment  in  the 
body,  than  what  happened  to  Admiral  Byron  and  Captains  Cheap 
and  Hamilton,  when  shipwrecked  on  the  wmst  coast  of  South  Ame- 
rica, w'ho,  after  suffering  months  of  hunger  and  fatigue,  were  re- 
duced to  skin  and  bone;  yet  when  they  came  to  good  living,  Byron 
thus  expresses  himself : “He  (viz.,  the  governor)  ordered  a table 
to  be  spread  for  us,  with  cold  ham  and  fowls,  which  only  we  three 
sat  down  to,  and  in  a short  time  despatched  more  than  ten  men  with 
common  appetites  would  have  done.  It  is  amazing  that  our  eating 
to  that  excess  we  had  done,  from  the  time  we  first  got  among  these 
kind  Indians,  had  not  killed  us  ; we  wmre  never  satisfied,  and  used 
to  take  all  opportunities,  for  some  months  after,  of  filling  our 
pockets  when  we  were  not  seen,  that  we  might  get  up  two  or  three 
-times  in  the  night  to  cram  ourselves.  Captain  Cheap  used  to  de- 
clare that  he  was  quite  ashamed  of  himself.” 

Spallanzani  has  made  several  attempts  to  prove  what  few  will 
subscribe  to,  that  stones  in  the  gizzards  of  birds  are  of  no  use 
tow^ards  the  breaking  or  grinding  down  the  grain  ; and  that  they 
are  picked  up  without  design.  These  stones  have  long  been  sup- 
posed to  answer  the  purposes-of  trituration,  and- have  been  con- 
sidered as  affording  assistance  to  the  stomach,  in  the  manner  of 
teeth,  and  of  course  as  being  necessary  to  the  act  of  digestion. 
Spallanzani  combats  this  opinion;  but  as  stones  are  .universally 
found  in  gizzards,  and  it  was  necessary  to  account  for  the  mode  of 
their  being  conveyed  there,  he  attributes  it  to  chance.  But  we  find 
that  the  gizzards  which  have  most  occasion  for  them,  and  are  most 
able  to  use  them,  are  likewise  best  supplied  with  them  : to  corrobo- 
rate which  facts  may  be  added  what  we  observed  before,  that  in 
the  larger  gizzards  are  found  the  largest  pebbles.  In  a turkey  two 
hundred  were  found  ; in  a goose,  a thousand  ; which  could  not  de- 
pend entirely  upon  chance.  In  trying  whether  the  stones  were  of 
service,  Spallanzani  introduced  tubes,  needles,  and  lancets  into  giz- 
zards in  which  there  were  but  very  few  stones,  yet  found  them 
broken.  In  this  experiment  these  substances  had  been  forty-eight 
hours  in  the  gizzards;  whereas  in  the  former  experiments,  with  the 
same  kind  of  tubes,  thirty-six  hours  was  the  longest  time;  in  another, 
eighteen  hours;  and  in  another,  the  breaking  of  them  was  begun  in 
less  than  two  hours ; therefore  the  experiments  were  not  perfectly 
fair,  as  the  times  were  not  equal.  What  he  thinks  the  most  con- 
clusive is,  that  where  he  had  taken  care  there  should  be  no  stones, 
the  hard  indigestible  substances  were  acted  upon  much  in  the  same 


120 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


way  as  when  there  were  stones ; bnt  in  this  experiment  he  does 
not  give  the  time,  which  is  very  accurately  stated  in  most  of  the 
others. 

He  discovered  that  the  inner  surface  of  the  stomach  was  not  hurt 
by  such  substances;  and  indeed  it  is  scarcely  possible  for  the  inner 
coat  of  the  stomach  of  a fowl  to  be  pierced  by  such  as  are  even 
sharp-pointed,  the  quantity  of  its  motion  being  so  inconsiderable  as 
hardly  to  make  them  pass  through  its  inner  coat.  But  the  principal- 
cause  of  their  being  harmless  arises  from  the  motion  being  lateral, 
and  not  pressing  perpendicularly  to  the  axis,  one  surface  sliding  in 
a contraiy  direction  to  the  other,  and  that  not  in  a straight,  but  in 
a circular  direction,  as  will  be  explained  hereafter. 

In  considering  the  strength  of  the  gizzard,  and  its  probable  effects 
when  compared  with  the  human  stomach,  it  must  appear  that  the 
gizzard  is  in  itself  very  fit  for  trituration;  we  are  not,  however,  to 
conclude  that  stones  are  entirely  useless ; for  if  we  compare  the 
strength  of  the  muscles  of  the  jaws  of  animals  which  masticate  their 
food  with  those  of  birds  which  do  not,  we  shall  say  that  the  parts 
are  well  calculated  for  the  purpose  of  mastication  ; yet  we  are  not 
from  thence  to  infer  that  the  teeth  i.n  such  jaws  are  useless,  even 
although  we  have  proof  that  the  gums  do  the  business  when  the 
teeth  are  gone.  If  stones  are  of  use,  which  we  may  reasonably 
conclude  they  are,  birds  have  an  advantage  over  animals  having 
teeth,  sO  far  as  stones  are  always  to  be  found,  while  the  teeth  are 
not  renewed.  Spallanzani  concludes,  “ That  W'e  have  at  length  a 
decision  of  the  famous  question  concerning  the  use  of  these  pebbles, 
so  long  agitated  by  authors  ; it  appearing  that  they  are  not  at  all 
necessa'ry  for  the  trituration  of  the  firmest  food,  &c,;”  but  says, 
“ He  will,  however,  not  deny  that  when  put  in  motion  by  the  gastric 
muscles,  they  are  capable  of  producing  some  effects  on  the  contents 
of  the  stomach.”  Now  if  we  constantly  find  in  an  organ  sub- 
stances which  can  only  be  subservient  to  the  functions  of  that 
organ,  should  we  deny  them  to  be  of  any  use  because  the  part  can 
to  a certain  degjree  do  its  office  without  them  ? 

To  account  for  pebbles  being  found  in  the  gizzard,  Spallanzani 
supposes  the  birds  to  have  picked  them  up  by  chance,  or  not  to 
have  distinguished  betwmen  their  food  and  these  stones.  But  it 
appears  singular  that  only  those,  which  have  gizzards  should  be  so 
stupid  ; and  he  owns  that  Redi  and  himself  found  that  birds  died  of 
hunger,  yet  without  having  picked  up  more  stones  than  usual,  which 
we  might  suppose  they  would  have  done  if  they  had  not  had  a 
choice,  or  could  not  have  distinguished  stones  from  the  grain  on 
which  they  feed. 

The  stones  assist  in  breaking  the  grain,  and  by  separating  its 
parts  in  the  beginning  of  the  process,  and  afteiavards  by  rubbing  oft’ 
the  surface  already  digested,  allow  the  gastric  juice  to  come  more 
completely  in  contact  with  the  whole. 

It  has  been-  said,  that  the  motion  of  the  gizzard  is  so  small  as 


OBSERVATIONS  ON  DIGESTION. 


121 


hardly  to  be  observable,  and  that  it  cannot  be  felt  by  the  hand. 
But  as  its  cavity  is  very  small,  and  must  be  capable  of  adapting 
itself  to  the  quantity  it  contains  (or  it  could  not  possibly  grind), 
much  motion  is  not  necessary  for  the  purposes  of  trituration:  a 
swelling  and  collapsing,  like  the  motion  of  the  heart,  would  have  no 
effect.  The  extent  of  motion  in  grindstones  need  not  to  be  the 
tenth  of  an  inch,  if  their  motion  is  alternate  and  in  contrary  di- 
rections. But  although  the  motion  of  the  gizzard  is  hardly  visible, 
yet  we  may  be  made  very  sensible  of  its  action  by  putting  the  ear 
to  the  sides  of  a fowl  while  it  is  grinding  its  food,  when  the  stones 
can  be  heard  moving  upon  one  another.* 

It  may  be  remarked,  that  the  motion  of  the  whole  intestinal  canal, 
from  the  fauces  to  the  anus,  is  naturally  so  slow,  as  not  to  be  ex- 
cited into  quick  actions.  The  food  passes  slowly  along  the  oeso- 
phagus ; and  in  a man,  fluids  which  might  be  expected  to  act  even 
by  their  own  gravity,  descend  but  slowly;  yet  1 think  we  may  be 
certain  that  the  oesophagus  has  always  a regular  contraction,  and 
that  the  lower  parts  must  relax  in  progression  as  it  contracts  above ; 
so  that  no  position  of  the  body  makes  any  difference  in  this  action. 

Upon  exposing  the  stomach  in  living  animals  it  does  not  appear 
much  agitated  or  affected,  even  by  being  handled  or  otherwise 
irritated.  The  same  thing  may  be  observed  in  the  whole  track  of 
intestines : and  we  find  that  when  the  faeces  ai'e  expelled  by  the 
action  of  the  gut  alone,  that  the  explusion  is  slow  ; the  stomach 
and  rectum,  however,  can  be  emptied  at  once  ; but  that  is  done  by 
the  abdominal  and  other  muscles.  We  know  that  the  action  of 
vomiting  is  performed  entirely  by  the  diaphragm  and  abdominal 
muscles  ; and  we  know  that  by  the  same  action  the  contents  of  the 
rectum  can  be  expelled.  Neither  is  any  other  power  required  to 
empty  the  stomach  in  vomiting,  these  muscles  being  often  capable 
of  forcing  the  bowels  themselves  out  of  the  abdomen,  and  of  pro- 
ducing a rupture.  It  is  not  necessary  the  stomach  itself  should  act 
violently  to  produce  an  evacuation  of  its  contents  ; nor  is  it  even 
necessary  it  should  act  at  all;  for  the  lungs  themselves  do  not  act 
in  the  least  when  any  extraneous  matter  is  to  be  thrown  up  ; and 
coughing  is  to  the  lungs  what  vomiting  is  to  the  stomach.f  The 

* [Harvey  makes  a similar  observation  on  birds  of  prey  : “Falconibus,  aquilis, 
aliisque  avibus  ex  praeda  viventibns,  si  anrem  prope  admoveris  dam  ventriculus 
jejunus  est,  manifestos  intus  strepitus,  lapiliorum  illiic  ingestorum,  invicemque 
collisorum  percipias.” — Opera  Unmia,  4to.,  p.  208.  These  investigations  by 
means  of  the  ear  relative  to  the  internal  actions  of  animal  bodies  deserve  a place  ' 
in  the  history  of  auscultation.] 

t [The  conclusion  which  Hunter  deduces  from  philosophical  and  just  analogies, 
with  respect  to  the  share  performed  by  the  stomach  in  the  act  of  vomiting,  has 
not  been  considered  satisfactory,  at  least  if  we  may  judge  from  the  experiments 
which  have  subsequently  been  made  with  a view  to  determine  that  point.  But 
perhaps  M.  Majendie  was  not  aware  of  what  our  illustrious  physiologist  had 
written  on  the  subject,  as  he  introduces  his  experiments  to  our  notice  as  if  the 
passive  state  of  the  stomach  in  vomiting  had  never  before  been  suspected  ; “ On 
a cru  long-temps  que  le  vomissement  dependaitde  la  contraction  brusque  et  con- 

12 


122 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


muscles  of  respiration  are  the  active  part  in  emptying  the  lungs, 
and  can  act  both  naturally  and  preternaturally.  The  muscles  of 
the  thorax  and  abdomen  do  not  act  naturally  on  the  contents  of 
the  abdomen,  but  often  act  preternaturally,  producing  an  evacua- 
tion from  its  viscera. 

There  is  this  difference  in  the  action  of  the  parts  in  coughing 
and  vomiting ; the  cough  is  performed  by  the  proper  muscles  of 
respiration,  which  are  those  of  expansion,  supported  by  the  abdo- 
minal, while  the  diaphragm  is  passive. 

Vomiting  is  performed  by  the  abdominal  muscles  and  diaphragm, 
wliile  those  of  inspiration  are  supporting  this  action. 

In  coughing  the  ribs  are  suddenly  depressed,  which  diminishes 
the  capacity  of  the  thorax  ; and  that  the  diaphragm  may  not  be 
allowed  to  sink  down  and  increase  the  capacity  of  the  thorax, 
which  would  counteract  the  depressors  of  the  ribs,  the  abdominal 
muscles  at  the  same  time  act,  which  supports  the  diaphragm  in  its 
place,  and  probably  may  by  this  action  assist  in  bringing  down  the 
ribs.  To  give  as  much  force  to  this  action  as  possible,  the  glottis 
is  shut  till  the  action  is  begun,  and  then  the  glottis  open  instan- 
taneously, which  obliges  the  depressors  of  the  ribs  to  begin  the 
effort  with  their  full  action. 

The  proper  muscles  of  inspiration  do  not  tire  so  soon  in  this 
action  as  the  abdominal,  for  in  violent  coughing  the  muscles  of  the 
abdomen  become  sore. 

In  vomiting  these  actions  are  reversed.  The  muscles  of  the 
cavity  of  the  abdomen  act,  in  which  is  to  be  included  the  diaphragm  ; 
so  that  the  capacity  of  the  abdomen  is  lessened,  and  the  action  of 
the  diaphragm  rather  raises  the  ribs ; and  there  is  also  an  attempt 
to  raise  them  by  their  proper  muscles,  to  make  a kind  of  vacuum 
in  the  thorax,  that  the  oesophagus  may  be  rather  opened  than  shut, 
while  the  glottis  is  shut  so  as  to  let  no  air  enter  the  lungs.  The 
muscles  of  the  throat  and  fauces  act  to  dilate  the  fauces,  which  is 
easily  felt  by  the  hand,  making  there  a vacuum,  or  what  is  com- 
monly called  a suction  ; so  that  when  all  these  actions  take  place 
together,  the  stomach  is  immediately  emptied. 

In  violent  coughing  we  find  that  a kind  of  mixed  action  takes 
place;  for  although  the  diaphragm  has  not  acted,  yet  the  stomach 
is  so  much  squeezed  as  to  discharge  its  contents;  and  it  affects  the 
diaphragm,  which  is  often  thrown  into  action,  and  brings  on  vomit- 
ing at  the  same  time;  therefore  violent  coughing  palls  the  stomach. 

There  is  reason  to  believe  that  the  natural  motion  in  all  stomachs 

Tulsive  de  I’estomac,”  &c.;  and  then  goes  on  to  detail  his  notorious  experiment 
on  the  dog,  for  whose  stomach  he  substituted  a pig’s  bladder;  by  which  he 
proved,  that  when  filled  with  fluid  and  put  into  a situation  to  be  pressed  upon, 
the  contents  of  the  bladder  would  flow  out.  By  dividing  the  phrenic  nerves,  and 
paralysing  the  diaphragm,  Majendie  also  proved  that  the  abdominal  muscles 
alone  were  capable  of  producing  vomiting  ; and  by  another  experiment,  he  satis- 
fied himself  that  the  diaphragm  alone  was  sufficient  for  that  act  when  all  the 
abdominal  muscles  had  been  dissected  off,  and  the  peritoneum  left  entire.] 


OBSERVATIONS  ON  DIGESTION. 


123 


is  regular;  and  I am  more  inclined  to  be  of  this  opinion  from  what 
takes  place  in  the  stomach  of  animals  which  are  covered  with  hair, 
and  which  lick  their  own  bodies,  and  of  such  as  feed  on  whole 
animals  which  are  likewise  covered  with  hair.  In  the  stomach  of 
the  calf,  for  instance,  which  licks  its  skin  with  its  tongue,  and 
swallows  whatever  is  attached  to  the  rough  surface  of  that  organ, 
balls  of  hair  are  often  found;  and  on  examining  their  surface  the 
hairs  in  each  hemisphere  seem  to  arise  from  a centre,  and  to  take 
the  same  direction,  which  is  circular,  corresponding  to  what  would 
appear  to  be  the  axis  of  this  motion,  and  resembling  what  we  see 
in  different  parts  of  the  skin  of  animals  whose  hair  takes  different 
turns.  This  regularity  in  the  direction  of  the  hair,  in  such  balls, 
could  not  be  produced  if  there  was  not  a regular  motion  in  the 
stomach.  This  motion  is  also  proved  in  the  dog ; for  I have  seen 
a ball  of  this  kind  that  had  been  thrown  up  from  a dog’s  stomach, 
w'here  the  same  regularity  in  the  turns  of  the  hair  was  very  evident 
and  complete.  The  same  motion  seems  also  to  take  place  in  the 
bird  kind  ; and  of  this  the  cuckoo  is  an  example,  which,  in  certain 
seasons  living  on  caterpillars,  some  of  which  have  hairs  of  a con- 
siderable length  on  their  bodies,  the  ends  of  these  are  found  sticking 
in  the  inner  horny  coat  of  the  stomach  or  gizzard,  while  the  hairs 
themselves  are  laid  flat  on  its  surface  ; not  in  every  direction,  which 
would  be  the  case  if  there  was  no  regular  motion,  but  all  one  way, 
arising  from  a central  point  placed  in  the  middle  of  the  horny  part, 
and  the  appearance  on  the  surface  of  both  sides  of  the  gizzard 
evidently  corresponding.*  These  two  facts  prove,  in  my  opinion, 
a regular  circular  motion  taking  place  in  the  gizzard  and  mem- 
branous stomach,  and  therefore,  most  probably,  something  similar 
is  carried  on  in  stomachs  of  all  the  various  kinds.  Indeed  this 
motion  in  the  stomach  is  so  considerable,  that  when  there  is  no 
horny  defence,  we  find  the  coats  sometimes  pierced  by  hard  pointed 
substances.  Thus,  the  cows  which  feed  on  the  grass  of  bleeching- 
grounds  have  their  stomachs,  especially  the  second  stuck  full  of 
pins;  and  fish  which  prey  upon  and  swallow  other  fish  entire,  often 
have  their  stomachs  pierced  by  the  bones. 

Spallanzani  calls  the  inner  coat  cartilaginous,  whereas,  in  fact,  it 
is  a horny  substance,  forming  an  inner  cuticle,  but  differing  in  some 
respects  from  the  common  cuticle ; this  horny  substance  not  only 
differs  in  structure  from  the  common  cuticle,  but  in  its  attachment, 
from  cuticle,  nails,  and  hoofs.  The  cutis  where  it  is  covered  by 
such  substances,  has  a vast  number  of  villi  on  its  surface,  which  pass 
into  corresponding  perforations  in  the  cuticle  ; from  this  structure 
of  parts,  when  the  cuticle,  nails,  or  hoofs  are  separated,  their  inner 

[The  appearance  is  so  regular,  that  this  hairy  lining  of  the  gizzard  has  been 
mistaken,  for  a natural  peculiarity  of  the  cuckoo.  In  one  of  these  gizzards, 
which  was  exhibited  at  a meeting  of  the  Zoological  Society,  I found  the  supposed 
gastric  hairs  under  the  microscope  to  present  the  complex  structure  characteristic 
of  those  of  the  larva  of  the  tiger-moth  {Arctia  Caja),  See  Proceedings  of  the 
Zool.  Soc.  1834,  p.  9.] 


124 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


surface  appears  to  be  full  of  small  perforations,  and  the  cutis  from 
which  they  have  been  removed  is  villous ; and  these  villi  are  more 
numerous  in  some  parts  than  in  others,  where  the  sense  of  touch  is 
required  to  be  delicate  or  acute.  But  the  inner  lining  of  the  gizzard 
is  just  the  reverse,  that  surface  of  the  horny  substance  which  is  in 
contact  with  the  gizzard  being  villous,  and  when  separated,  the 
inner  surface  of  the  gizzard  appearing  perforated.  These  villi  are 
either  the  last-formed  parts  of  this  horny  substance,  or  are  the  fibres 
of  which  the  horny  coat  is  composed.  It  is  probable  that  this 
horny  substance  takes  the  form  of  villi  that  it  may  be  more  firmly 
connected  with  the  gizzard,  in  which  acute  sensation  is  not  required. 

I may  remark  here,  that  the  experiments  made  on  the  digestion 
of  ruminating  animals  have  been  very  deficient,*  arising  from 
this  process  in  them  being  more  complicated  than  in  the  stomachs 
of  other  animals,  and  requiring  attention  to  be  paid  to  certain 
circumstances,  which  cannot  take  place  in  stomachs  of  only  one 
cavity. 

The  circumstance  mentioned  by  Spallanzani,  of  ruminating 
animals  voiding  the  tubes  by  the  anus,  shows  that  the  whole  food 
is  not  necessarily  returned  into  the  mouth  to  be  chewed  a second 
time;  for  if  it  W'ere,  the  tubes  would  certainly  come  up  likewise, 
and  would  as  certainly  be  thrown  out  of  their  mouths  as  improper 
to  be  chewed,  a circumstance  which  often  really  happened.  But  it 
W'as  hardly  necessary  to  make  experiments  to  ascertain  whether 
ruminating  animals  digested  meat,  M'hen  we  know  that  in  some 
cold  countries  the  cattle  are  fed  on  dried  fish,  and  most  animals  eat 
their  own  secundines:  indeed  the  circumstance  of  animals  living 
upon  both  animal  and  vegetable  food  might  have  taught  us  that  the 
mode  of  digesting  both  (whatever  it  is)  was  the  same;  therefore 
all  that  was  wanted  must  have  been  to  discover  that  mode ; except 
W'e  could  absurdly  conceive  that  two  diflerent  modes  might  take 
place  in  the  same  stomach  at  the  same  time. 

Spallanzani  gives  the  opinion  of  authors  respecting  digestion; 
and  so  anxious  is  he  to  combat  the  idea  of  its  being  fermentation, 
that  he  will  hardly  allow  that  fermentation  ever  takes  place  in  the 
stomach.  That  fermentation  can  go  on  in  the  stomach  there  is 
no  doubt ; but  when  that  happens,  it  arises  from  the  powers  of 
digestion  being  defective.  Milk,  vegetables  of  all  kinds,  wine,  and 
whatever  has  sugar  in  its  composition,-  become  much  sooner  sour 
in  some  stomachs  than  they  would  if  left  to  undergo  a spontaneous 
change  out  of  the  body;  and  even  spirits  in  particular  stomachs, 
almost  immediately  degenerate  into  a very  strong  acid.  I am 
inclined  to  suppose  that  it  is  the  sugar  which  is  converted  into 
spirit,  and  the  spirit  into  acid  ; consequently  a glass  of  brandy, 
from  being  much  stronger,  because  less  diluted,  most  probably 

* [This  deficiency  has  recently  been  supplied  by  M.  Flourens,  in  an  elaborate 
series  of  experiments  made  on  living  sheep,  in  which  fistulous  communications 
had  been  established  between  the  external  surface  and  the  different  cavities  of 
the  stomach.  See  Jlnnales  des  Sciences  Naturelles.'] 


OBSERVATIONS  ON  DIGESTION. 


125 


contains  as  much  matter  likely  to  become  acid  as  half  a pint  of 
wine.  In  other  substances,  besides  those  mentioned  above,  the 
fermentative  process  (unless  prevented  by  that  of  digestion)  appears 
to  begin  sooner  in  the  stomach  than  out  of  the  body.  All  oily 
substances,  particularly  butter,  very  soon  become  rancid  after 
being  taken  into  the  stomach ; and  this  rancidity  is  the  effect  of 
the  first  process  of  the  fermentation  of  oil.  Mr.  Sieffert  has  been 
able  to  restore  rancid  oils  to  their  original  sweetness,  by  adding  to 
them  their  due  quantity  of  fixed  air;*  the  loss  of  which  I consider 
as  the  first  process  in  this  fermentation,  similar  to  what  happens  in 
the  fermentation  of  animal  and  vegetable  substances. 

Animal  food  does  not  so  readily  ferment  in  the  stomach  when 
combined  with  vegetables  as  when  it  is  not ; for  the  vegetables 
running  more  quickly  into  fermentation,  preserve  the  meat  from 
putrefaction.  Put  a piece  of  meat  and  some  sugar,  or  bread,  into 
water,  and  let  them  stand  in  a warm  place;  the  bread  and  sugar 
will  begin  to  ferment,  the  water  will  become  sour,  and  the  meat  be 
preserved  ; but  the  acid  becoming  weaker,  as  the  fermentation 
advances  towards  the  putrefactive,  the  meat  at  last  begins  to  acquire 
the  same  putrid  disposition.!  Yet  this  last  part  of  the  process  can- 
not, I think,  take  place  in  the  stomach,  as  a succession  of  acids  will 
be  formed,  by  which  the  meat  will  be  preserved  sweet  till  it  is 
digested  ; the  formation  of  this  acid  in  the  stomach,  most  probably, 
not  preventing  the  digestion  of  those  substances  which  are  incapable 
of  being  rendered  acid. 

Bread  allowed  to  remain  in  the  stomach  of  a dog  for  eight  hours 
is  so  much  changed  that  it  will  not  run  into  the  vinous  fermentation, 
but  when  taken  out  and  kept  in  a warm  place  becomes  putrid ; its 
putrefaction,  however,  is  not  so  quick  as  a solution  of  meat  that  has 
been  in  the  stomach  for  the  same  length  of  time.  Similar  effects 
are  produced  when  milk  and  bread  are  the  food  administered;  and 
perhaps  the  gastric  juice,  when  in  sufficient  quantity,  will  always 
prevent  the  vinous  fermentation. 

Spallanzani’s  next  trials  were  to  determine  whether  the  gastric 
juice  had  the  power  of  recovering  meat  already  putrid  : a fact 
which  might  have  been  proved  by  one  experiment;  for  if  very 
putrid  meat  is  given  to  a dog,  and  the  dog  killed  after  some  time, 
the  meat  will  be  found  sweet,  and  all  putrefaction  at  an  end. 
Therefore  his  allowing  fresh  meat  to  continue  a longer  or  shorter 
time  in  the  stomach  was  immaterial,  as  it  could  not  become 
putrid. 

It  appears  from  the  above  facts  that  the  stomach  has  not  so 
much  power  in  preventing  the  acetous  fermentation  in  vegetables 
as  in  correcting  the  putrefactive  disposition  in  animal  substances. 
For  although  this  cannot  be  certainly  known  in  those  who  eat  both 

* Physical  and  Chemical  Essays,  by  SirTobern  Bergman. 

I Of  this  Sir  John  Pringle  was  not  aware  in  making  his  experiments  on  this 
subject. 


12* 


126 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


animal  and  vegetable  food,  yet  it  does  not  appear  tliat  the  putre- 
faction of  animal  substances,  where  nothing  else  is  eaten,  takes 
place  so  quickly  in  the  stomach  as  the  change  which  is  produced 
in  vegetables ; the  acetous  disposition  is  therefore  either  stronger 
than  the  putrefactive,  or  it  more  readily  takes  place:  and  indeed 
the  living  body  shows  this  sufficiently;  for  we  very  often  find  an 
acid  thrown  up,  but  seldom  or  never  anything  putrefactive. 

It  may  be  admitted  as  an  axiom  that  two  processes  cannot  go  on 
at  the  same  time  in  the  same  part  of  any  substance ; therefore 
neither  vegetable  nor  animal  substances  can  undergo  their  spon- 
taneous changes  while  in  the  act  of  being  digested,  it  being  a pro- 
cess superior  in  power  to  that  of  fermentation.  But  if  the  digestive 
power  is  not  perfect,  then  the  vinous  and  acetous  fermentation  will 
take  place  in  the  vegetable,  and  the  putrefactive  in  the  food  of  those 
animals  which  live  wholly  on  flesh  ; although  in  the  last  I imagine 
but  very  seldom.  The  gastric  juice,  therefore,  preserves  vegetables 
from  running  into  fermentation,  and  animal  substances  from  putre- 
faction ; not  from  an}'  antiseptic  quality  in  the  juice,  but,  by  making 
them  go  through  another  process,  preventing  the  spontaneous 
change  from  taking  place.  In  the  greater  number  of  stomachs 
there  is  an  acid,  even  although  the  animal  has  lived  upon  meat  for 
many  weeks;  but  as  this  is  not  always  the  case,  we  must  suppose 
it  is  only  formed  occasionally.  Whether  the  stomach  has  a power 
of  immediately  secreting  this  acid,  or  first  secretes  a sugar  which 
afterwards  becomes  acid,  is  not  easily  ascertained;*  but  I should 
be  inclined  to  suppose,  from  analogy,  the  last  to  be  the  case  : 
animals  in  health  seeming  to  have  the  power  of  secreting  sugar; 
for  we  find  it  in  the  milk,  and  sometimes  in  the  urine,  in  conse- 
quence of  disease.  Acid  sometimes  prevails  in  the  stomach  to  so 
great  a degree  as  to  become  a disease,  attended  with  very  disagree- 
able symptoms;  the  stomach  converting  all  substances  which  have 
a tendency  to  become  acid  into  that  form.  To  ascertain  whether 
there  was  an  acid  naturally  in  the  stomach  the  most  satisfactory 
mode  was  to  examine  the  contents  before  the  birth,  when  the  diges- 
tive organs  are  perfect,  and  when  no  acid  could  have  been  pro- 
duced by  disease,  or  anything  that  had  been  swallowed.  Ac- 
cordingly, in  the  slink-calf,  near  the  full  time,  there  was  no  acid 
found  in  the  stomach,  although  the  contents  had  the  same  coagulat- 
ing powers  with  those  of  animals  who  have  sucked. 

As  we  find  stomachs  possessed  of  a power  of  dissolving  the 

* [The  singular  case  of  the  man  with  an  external  fistulous  communication  with 
the  stomach,  detailed  by  Mr.  Beaumont,  who  has  so  ably  availed  himself  of  the 
circumstance  to  elucidate  several  obscure  points  in  the  process  of  digestion,  has 
att’orded  the  means  of  determining  this  question.  The  stomach  in  its  empty  and 
inactive  state  contains  no  gastric  juice;  but  when  mechanically  stimulated,  as 
by  touching  the  inner  surface  with  the  bulb  of  a thermometer  that  secretion  is 
immediately  poured  out,  and  manifests  the  usual  acid  properties.  (Beaumont: 
“ Experiments  and  Observations  on  the  Gastric  Juice,  and  on  the  Physiology  of 
Digestion.”)] 


OBSERVATIONS  ON  DIGESTION. 


127 


whole  substance  of  a bone,  it  is  reasonable  to  suppose  that  its  earth 
is  destroyed  by  the  acid  in  the  stomach. 

The  stomach  appears  not  only  to  be  capable  of  generating  an 
acid,  but  also  to  have  the  power  of  producing  air  ; which  last  effect, 
I believe,  arises  from  disease.  It  is  not  easy  to  account  for  the 
formation  of  this  air;  yet  as  the  stomach  is  a reservoir  for  sub- 
stances disposed  to  ferment,  it  might  reasonably  be  supposed  to 
arise  from  the  food  going  into  that  process.  But  this,  in  my 
opinion,  will  not  account  for  the  vast  quantity  of  air  frequently 
thrown  up  from  the  stomach,  even  where  food  has  not  been  swal- 
lowed for  a considerable  time,  and  where  digestion  appeared  to 
have  been  completed.  For  we  must  conclude  this  process  to  have 
been  completed,  if  the  food  was  not  found  to  have  disagreed  with 
either  stomach  or  bowels,  and  that  the  stools  were  good.  When 
the  gout  falls  on  the  stomach  the  quantity  of  air  thrown  up  is  often 
immense,  and  the  same  thing  may  be  observed  in  some  cases  com- 
monly called  nervous  ; yet  the  process  of  digestion  will  not  account 
for  this  formation  of  air,  as  no  air  is  to  be  found  in  healthy 
stomachs  ;*  neither  is  it  to  be  accounted  for  from  a defect  in 
digestion,  as  that  w'ould  probably  be  productive  of  worse  conse- 
quences. 

I am  inclined  to  believe  that  the  stomach  has  a power  of  forming 
air,  or  letting  it  loose,  from  the  blood,  by  a kind  of  secretion.  We 
cannot,  however,  bring  any  absolute  proof  of  this  taking  place  in 
the  stomach,  as  it  may  in  all  cases  be  referred  to  a defect  in 
digestion;  but  we  have  instances  of  air  being  found  in  other  cavi- 
ties, where  no  secondary  cause  can  be  assigned.  I have  been 
informed  of  persons  who  have  had  air  in  the  uterus  or  vagina, 
without  having  been  sensible  of  it  but  by  its  escaping  from  them 
without  their  being  able  to  prevent  it;  and  who,  from  this  circum- 
stance, have  been  kept  in  constant  alarm  lest  it  should  make  a 
noise  in  its  passage,  having  no  power  to  retard  it  as  when  it  is 
contained  in  the  rectum.  This  fact  being  so  extraordinary  made 
me  somewhat  incredulous,  but  rendered  me  more  inquisitive,  in  the 
hope  of  being  enabled  to  ascertain  and  account  for  if;  and  those  of 
whom  I have  been  led  to  inquire  have  always  made  the  natural 
distinction  between  air  passing  from  the  vagina  and  by  the  anus : 
that  from  the  anus  they  feel  and  can  retain,  but  that  in  the  vagina 
they  cannot;  nor  are  they  aware  of  it  till  it  passes.  A woman, 
whom  I attended  with  the  late  Sir  John  Pringle,  informed  us  of 
this  fact,  but  mentioned  it  only  as  a disagreeable  thing.  I w’as 
anxious  to  determine  if  there  were  any  communication  between 
the  vagina  and  rectum,  and  was  allowed  to  examine,  but  disco- 
vered nothing  uncommon  in  the  structure  of  these  parts.  She  died 
some  time  after ; and,  being  permitted  to  open  the  body,  I found 
no  disease  either  in  the  vagina  or  uterus.  Since  that  time  I have 

* In  all  my  experiments  on  digestion,  in  dogs,  I have  never  been  able  to  detect 
any  air  in  the  cavity  of  the  stomach. 


128 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


had  opportunities  of  inquiring  of  a number  of  women  concerning 
this  circumstance,  and  by  three  or  four  have  been  informed  of  the 
same  fact,  with  all  the  circumstances  above-mentioned.  How  far 
they  aie  to  be  relied  upon  1 will  not  pretend  to  determine.  I have 
likewise  found  air  in  the  cellular  membrane  in  gunshot  wounds, 
that  had  passed  some  way  under  the  skin,  without  being  able  to 
account  for  its  being  there  by  any  mechanical  effect  of  the  ball. 

That  air  is  either  formed  from  the  blood,  or  let  loose  by  some 
action  of  the  vessels,  both  naturally  and  from  disease,  is  an  unde- 
niable fact.  We  find  air  formed  in  some  fishes,  to  answer  natural 
purposes;  for  in  those  whose  air-bladders  do  not  communicate 
externally  (many  of  which  there  are)  we  must  suppose  it  to  have 
been  formed  there.  We  also  find  it  in  animals  after  death;  and  I 
have  a piece  of  the  intestine  of  a hog  which  has  a number  of  air- 
bladders  in  it.  Mr.  Cavendish  was  so  kind  as  to  examine  this  air, 
and  he  found  “ it  contained  a little  fixed  air;  and  the  remainder 
not  at  all  inflammable,  and  almost  completely  phlogisticated.”  I 
have  often  seen  such  vesicles  on  the  edges  of  the  lungs;  but  these 
may  be  supposed  to  have  been  a kind  of  aneurismal  air-cells  filled 
from  the  trachea,  and  are  circumscribed  and  impervious,  so  that  in 
the  state  we  find  them  they  have  no  communication  with  the  exter- 
nal air.  In  one  instance  I have  discovered  air  in  an  abscess,  which 
could  not  have  been  received  from  the  external  air,  nor  could  it 
have  arisen  from  putrefaction.  The  case  is  as  follows: 

A lady,  about  forty  years  of  age,  had  been  afflicted  with  com- 
plaints in  the  bladder  and  parts  connected  with  it.  From  the  symp- 
toms, her  disease  was  supposed  by  some  to  be  the  stone,  though 
upon  examination  no  stone  was  found  ; and  she  had  also  an  umbi- 
lical hernia,  for  which  I had  been  consulted.  She  grew  gradually 
worse,  and  from  being  lusty,  becaiue  a thin  woman.  A small 
tumour  appeared  in  the  groin,  and  the  skin  over  it  became  red, 
similar  to  an  abscess  when  the  matter  is  beginning  to  point  exter- 
nally; but  before  her  death  this  subsided.  A few  days  before  she 
died  I was  desired  to  examine  a swelling  on  the  lower  and  right 
side  of  the  belly,  extending  nearly  from  the  navel  to  the  spine  of 
the  ilium  on  the  right  side.  It  was  tense,  evidently  contained  air, 
and  could  be  made  to  sound  almost  like  a drum.  It  had  come  on 
within  a few  weeks,  and  I was  puzzled  to  account  for  it,  there  being 
clearly  no  connexion  between  that  tumour  and  the  umbilical  hernia. 
I was  inclined  to  suppose  it  to  be  a ventral  hernia,  containing  the 
caecum  and  part  of  the  colon,  filled  with  air;  but  as  she  had  stools, 
as  there  were  no  symptoms  of  a strangulated  gut  nor  any  uneasi- 
ness in  the  bowels,  as  I could  not  make  the  air  recede,  but  felt  it  as 
if  confined  to  that  part,  I own  I could  form  no  conjecture  what  the 
case  really  was.  The  woman  dying  in  a few  days,  I was  permitted 
to  examine  the  body.  That  I might  not  interfere  with  the  tumour, 
or  umbilical  hernia,  I made  an  opening  into  the  abdomen  on  the 
right  side  of  the  linea  alba,  and  on  examining  the  cavity  of  the  ab- 
domen, found  everything  natural,  except  a small  portion  of  the  epi- 


OBSERVATIONS  ON  DIGESTION. 


129 


ploon  adhering  to  the  inside  of  the  navel ; the  parietes  of  the  abdo- 
men corresponding  with  the  tumour  being  in  a natural  state.  On 
pressing  the  tumour  by  the  hand,  air  was  heard  to  make  its  escape; 
whether  by  the  vagina  or  anus  was  at  first  doubtful ; but  on  ex- 
amining with  more  attention,  it  was  discovered  to  come  from 
between  the  labia,  I next  opened  the  tumour  externally,  and  let 
out  the  air,  which  was  not  in  the  least  putrid,  and  was  contained 
in  a sac  tolerably  smooth  on  its  inside,  made  up  of  compressed  cel- 
lular membrane,  the  abdominal  muscles  and  tendons  forming  the 
posterior  surface,  which  extended  as  low  as  the  inferior  edge  of 
Poupart’s  ligament.  The  contents  of  the  abdomen  were  tolerably 
sound ; but  when  I inspected  the  viscera  contained  in  the  pelvis, 
they  were  found  adhering  to  each  other ; the  bladder  to  the  body 
of  the  uterus  : the  broad  ligaments  and  ovaria  to  the  uterus ; and 
on  examining  these  adhesions,  I discovered  a cavity  between  the 
bladder,  uterus,  and  vagina,  on  the  right  side,  something  like  an 
abscess.  From  the  right  side  of  this  cavity  there  was  a canal  as- 
cending to  the  brim  of  the  pelvis,  in  the  course  of  the  round  liga- 
ment, as  far  as  to  the  going  out  of  the  iliac  vessels,  which  it  seemed 
to  accompany ; and  this  canal,  when  it  passed  from  behind 
Poupart’s  ligament,  communicated  with  the  tumour  above  men- 
tioned. I then  endeavoured  to  discover  if  there  were  any  com- 
munication between  the  rectum  and  the  abscess,  but  could  find 
none,  the  gut  appearing  to  be  quite  sound.  Having  removed  the 
whole  contents  of  the  pelvis,  with  the  canal  leading  to  Poupart’s 
ligament,  and  the  ligament  itself,  witli  such  of  the  abdominal  muscles 
as  composed  part  of  the  sac,  I found  both  the  rectum  and  the  vagina 
perfectly  sound.  The  uterus  had  a polypus  forming  on  its  inside; 
neither  the  rectum  nor  uterus  had  any  connexion  with  the  abscess; 
but  there  was  a small  communication  between  the  abscess  and  the 
bladder,  that  portion  of  the  bladder  which  made  part  of  the  abscess 
being  very  much  diseased. 

From  this  history  of  the  appearances  of  the  tumour  before  death, 
and  the  particular  account  I have  given  of  the  dissection,  the  reader 
may  be  able  to  draw  his  own  conclusions  relative  to  the  origin  of 
the  air.  It  certainly  appeared  to  have  been  formed  in  this  bag; 
and  it  was  only  towards  the  latter  end  of  her  life  that  it  could  have 
made  its  escape  into  the  cavity  of  the  bladder,  for  it  was  not  possible 
to  squeeze  the  air  out  of  the  tumour  when  I first  saw  her ; but  just 
before  death  it  became  more  flaccid.  It  could  not  be  formed  or 
let  loose,  in  consequence  of  putrefaction,  for  the  air  itself  was  free 
from  any  smell  ; and  although  the  cavity  between  the  vagina  and 
bladder  had  on  its  internal  surface  the  irregular  ulcerated  appear- 
ance of  an  abscess,  yet  that  on  the  abdomen  had  not,  was  tolerably 
smooth,  and  had  rather  the  appearance  of  having  been  formed  in 
consequence  of  some  foreign  matter  accumulating  there. 

This  circumstance,  of  an  animal  having  the  power  of  forming 
air,  or  separating  it  from  the  juices  by  a kind  of  secretion,  appears 


130 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


at  first  view  to  be  supported  by  the  experiments  of  Dr.  Ingen- 
housz.* 

The  Doctor  observed,  that  when  we  immerse  our  bodies  “ in  a 
cold  or  warm  bath,”  or  “ by  plunging  the  hand  and  arm  even  in 
cold  w'ater,”  globules  of  air  soon  appear  upon  the  skin  ; and  to  be 
certain  of  the  air  coming  from  the  body,  he  took  all  the  necessary 
precautions  to  prevent  the  external  air  being  carried  into  the  water 
along  with  the  body  (which  w'ould  certainly  be  a consequence  if  the 
body  or  part  w'ere  immersed  quickly,  or  when  dried).  But  although 
his  experiments  seem  to  prove  this  opinion,  yet  I imagine  there  is  a 
circumstance  the  Doctor  did  not  attend  to  at  the  time,  which  renders 
them  very  fallacious  ; for  he  did  not  consider  that  water  for  the 
most  pan  contaitis  a great  deal  of  air;  therefore  the  globules  of  air 
might  as  readily  come  from  the  water  as  from  the  body,  which 
makes  it  necessary  to  ascertain,  by  experiment,  from  whence  the 
air  comes  which  is  attached  to  the  body  when  immersed  in  water. 

Water  takes  up  air  in  proportion  to  its  coldness,  until  it  loses 
the  property  of  water,  and  becomes  solid  : upon  this  principle  we 
may  account  for  globules  of  air  being  found  attached  to  the  skin 
when  a part  of  the  body  is  immersed  in  water  colder  than  itself;  for 
w'hen  we  immerse  the  whole  body  we  increase  the  heat  of  the 
water,  especially  that  next  to  the  skin;  and  if  we  immerse  only  a 
part,  as  an  arm,  it  being  commonly  in  a smaller  quantity  of  water, 
the  W'ater  immediately  surrounding  it  is  also  warmed.  As  a proof 
that  it  is  the  air  from  the  water,  and  not  from  the  surface  of  the 
body,f  it  matters  not  what  the  substance  is  that  is  immersed  if  it  is 
but  warmer  than  the  water ; for  a piece  of  iron,  heated  to  about 
150°,  immersed  in  water  about  70°,  will  warm  the  water  in  contact 
with  it  so  as  to  make  it  part  with  its  air.  This  effect  of  heat  is 
further  proved  by  making  another  trial,  with  only  this  difference, 
that  the  iron  be  ten  degrees  colder  than  the  water ; in  that  case 
little  or  no  air  wdll  be  separated,  and  of  course  no  bubbles  observed. 
The  bubbles  of  air  do  not  appear  to  arise  entirely  from  the  degree 
of  warmth  of  the  water,  but  also  in  some  measure  from  a solid 
body  being  immersed  in  it,  that  seems  to  have  a power  of  attract- 

* Experiments  upon  Vegetables,  proving  their  great  power  of  purifying  the 
common  air,  &c. 

I “ Count  cle  Milly,  in  the  Berlin  Transactions  for  the  year  1777,  published 
experiments  to  show  that  there  is  an  excretion  of  air,  or,  as  it  is  termed,  ‘an 
aerial  transpiration,’  from  the  whole  surface  of  the  human  body  while  it  remains 
in  warm  water ; but  Dr.  Pearson  found,  on  repeating  these  experiments,  that 
there  was  no  appearance  of  aerial  bubbles  on  the  surface  of  the  cuticle  during 
bathing  in  warm  water  that  had  been  previously  boiled,  so  as  to  expel  the  air 
usually  mixed  and  united  to  river  and  spring  water.  The  human  body,  when 
immersed  in  the  bath  at  Buxton,  and  kept  at  rest  in  it  for  some  time,  was  covered 
with  air-like  bubbles;  but  these  bubbles  appeared  in  the  same  manner  on  any 
solid  body  w'hatever  that  was  placed  in  it.  It  is  therefore  supposed  that  the 
attraction  to  the  human  body  of  the  air,  commonly  suspended  in  water,  especially 
when  heated  to  the  temperature  of  a warm-water  bath,  has  been  mistaken  for  an 
excretion  of  air  from  the  cuticle.” 


OBSERVATIONS  ON  DIGESTION. 


131 


ing  the  air,  whose  affinity  to  the  water  is  now  weakened  by  heat; 
for  simply  heating  the  water  to  the  same  degree  will  not  separate 
the  air,  as  we  find  that  no  bubbles  are  then  produced.  The  power 
of  attracting  the  air  appears  therefore  in  some  sort  to  depend  upon 
the  solidity  of  the  body  immersed;  at  least  bodies  have  a greater 
number  of  bubbles  in  proportion  to  their  solidity ; for  upon  making 
comparative  experiments  between  iron,  stone,  wood,  and  cork,  the 
air  separated  from  the  water  upon  the  surface  of  the  iron  and  stone 
is  in  considerable  quantity  ; that  upon  the  wood  very  small,  and 
scarcely  any  at  all  upon  the  cork. 

As  these  observations  on  the  generation  (or  secretion)  of  air  in 
cavities  seemed  to  have  a connexion  with  the  present  inquiry,  I 
thought  they  might  properly  enough  be  introduced  here  ; but  I shall 
content  myself  with  having  mentioned  the  circumstance,  and  pursue 
the  subject  of  digestion. 

To  determine  with  absolute  certainty  in  what  particular  portion 
of  the  canal  this  important  process  of  digestion  is  performed,  is 
perhaps  impossible ; but  there  is  the  greatest  reason  to  believe  that 
it  is  principally  carried  on  in  the  stomach,  with  a little  variation 
in  different  animals.  We  may  venture  to  affirm  that  it  does  not 
at  all  take  place  in  the  long  and  contracted  oesophagus  of  the 
quadruped,  the  secretion  of  that  part  being  a slimy  mucus,  possessed 
of  no  power  similar  to  that  of  the  gastric  juice,  but  only  intended 
to  facilitate  the  passage  of  the  food  into  the  stomach. 

Neither  has  the  mucus  secreted  in  certain  parts  of  the  oesophagus 
of  birds,  as  in  the  crop  of  those  which  have  one,  any  digestive 
power  ; W'hile,  on  the  contrary,  we  find  the  lower  end,  which  is 
extremely  glandular,  to  be  capable  of  secreting  a juice  with  all  the 
properties  of  the  gastric  ; and  that  passing  into  the  cavity  of  the 
stomach  becomes  a substitute  in  this  class  of  animals  for  the  de- 
ficiency of  the  secretion  of  the  stomach  itself,  which  in  some  is 
lined  with  a horny  substance,  and  in  others  with  a cuticle.  Even 
in  birds  the  seat  of  digestion  is  chiefly  in  the  stomach,  the  juice 
secreted  in  the  lower  part  of  the  msophagus  passing  into  that  cavity ; 
and  the  mucus  secreted  by  the  other  parts  of  the  oesophagus,  as  in 
the  crop  of  those  which  have  one,  has  no  such  power.  But  if  any 
digestible  substance  should  be  retained  in  the  oesophagus,  as  may 
happen  in  many  of  those  which  swallow  whole  animals,  digestion 
may  even  go  on  in  its  inferior  portion.  In  the  gull  and  heron, 
which  take  down  snakes  and  fish  entire,  the  tails  may  remain  in 
the  oesophagus  till  the  head  is  digested  in  the  stomach  ; and  in  such 
cases  the  tail  itself  may  be  acted  upon  in  that  situation. 

As  a further  proof  that  digestion  is  carried  on  principally  in  the 
stomach,  let  us  observe  what  happens  to  the  yolk  of  an  egg  in  the 
bird  newly  hatched.  The  yolk  is  not  in  the  least  consumed  in 
the  time  of  incubation,  but  appears  to  be  reserved  for  the  nourish- 
ment of  the  chick  between  the  time  of  hatching,  and  its  either 
being  supplied  with  food  by  its  parents,  or  being  able  to  procure  it 
for  itself;  for  we  find,  that  although  the  yolk  passes  into  the  gut  at 


132 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


some  distance  from  the  stomach,  yet  it  is  carried  up  to  the  stomach 
to  be  digested  ; and  I have  even  seen  it  in  the  crop,  being  retained 
there  till  wanted. 

In  those  animals  whose  stomach  consists  of  several  cavities,  the 
precise  place  where  digestion  is  carried  on  has  not  been  ascertained. 

I think,  however,  that  in  the  ruminating  class,  in  which  it  has  four 
cavities,  it  may  be  set  down  as  a fact  that  digestion  goes  on  in  the 
fourth,  which  is  best  proved  by  feeding  the  animal  with  a substance 
that  does  not  require  any  kind  of  preparation  for  digestion,  such  as 
milk.  If  a calf  be  killed  about  half  an  hour  after  it  has  sucked  its 
mother,  we  shall  find  the  whole  milk  in  the  fourth  cavity  firmly 
coagulated,  and  formed  into  a ball,  while  the  first,  second,  and  third 
cavities  contain  only  such  food  as  requires  mastication,  or  what 
other  preparation  is  necessary  to  fit  it  for  digestion.  Such  animals 
have  the  power  of  conveying  the  food  from  the  oesophagus,  either 
to  the  first  or  fourth  cavity,  according  to  the  nature  of  the  food ; 
and  for  this  purpose  there  is  a groove  leading  directly  from  the 
oesophagus  to  the  fourth  stomach,  which  I suppose  can  be  converted 
into  a canal  when  wanted. 

It  is  possible  that  digestion  may  likewise  be  carried  on  in  the 
duodenum,  especially  in  its  upper  part,  if  either  the  intestine  secretes 
the  same  juice  with  the  stomach,  or  that  some  of  the  gastric  juice 
and  part  of  the  food  have  passed  into  the  intestine  before  it  has 
been  completely  turned  into  chyle.* 

Although  the  stomach  is  the  seat  of  digestion,  it  is  not  solely  ap- 
propriated to  that  purpose;  and  in  many  animals  these  organs  are 
not  to  be  considered  as  only  a digesting  bag  or  bags,  but  in  part 
as  a reservoir  for  food.  This  is  most  remarkable  in  the  ruminating 
animals,  where  the  first  stomach  or  bag  is  merely  a reservoir,  and 
in  this  respect  analogous  to  a crop.  It  is  the  same  in  the  porpus, 
and,  I believe,  in  most  animals  of  this  class;  although  it  cannot  be 
supposed  that  those  return  the  food  who  have  not  the  power  to 
masticate.  In  some  animals  which  do  not  ruminate  there  is  not 
the  same  necessity  for  distinct  pouches,  the  stomach  consisting 
either  of  one  bag  singly,  or  of  stomach  with  appendages,  as  in  the 
peccari.  But  the  whole  organ  is  not  endowed  with  the  property  of 
secreting  the  gastric  juice,  there  being  a part  whose  structure  is 
very  diflerent  from  that  appropriated  to  digestion,  and  covered  by 

* [This  conjecture  is  confirmeil  by  the  observations  of  Tiedemann  and  Gmelin, 
who  found  that  when  any  vegetable  fecula  passed  the  pylorus  unaltered  it  was 
converted  in  the  duodenum,  as  in  the  stomach,  into  sugar  and  amydine. 

Majendie  attempted  to  subject  this  question  to  direct  experiment,  but  failed 
from  not  having  insured  the  continuance  of  the  substance  experimented  on  in  the 
necessary  situation.  He  found,  on  introducing  a piece  of  raw  flesh  into  the 
duodenum  of  a healthy  dog,  that  in  an  hour  it  had  been  carried  to  the  rectum  : its 
weight  was  slightly  diminished,  but  there  was  no  other  change  than  a discolora- 
tion of  its  surface.  In  another  experiment  he  fixed  a morsel  of  flesh  in  the  small 
intestine  with  a thread;  after  the  lapse  of  three  hours  it  had  lost  about  half  its 
weight:  the  fibrin  had  been  principally  acted  upon  ; what  was  left  was  entirely 
cellular,  and  extremely  foetid.  See  Precis  Elementaire  de  Physiologic,  ii.  p.  114.] 


OBSERVATIONS  ON  DIGESTION. 


133 


a cuticle,  as  in  the  first,  second,  and  third  stomach  of  the  ruminat- 
ing animals  and  in  the  first  stomach  of  the  porpus.  The  peccari, 
the  common  hog,  and  the  rat,  ai’e  likewise  instances  of  this; 
and  the  same  circumstance  takes  place,  in  a smaller  degree,  in  the 
horse. 

This  increase  in  the  cavity  of  the  stomach,  beyond  what  is  neces- 
sary for  digestion  alone,  is  peculiar  to  the  animals  that  take  in  more 
food  than  is  immediately  wanted,  or  whose  food  is  of  a nature 
which  requires  a certain  degree  of  preparation  prior  to  digestion. 
The  crop  of  the  eagle,  and  perhaps  the  first  stomach  of  the  porpus, 
are  of  the  first  kind ; the  crop  in  the  gallinaceous  fowls,  and  the 
first  stomach  in  ruminating  animals,  of  the  second.*  It  is  the  dis- 
position of  such  animals  to  fill  these  cavities  ; and  the  quantity 
which  they  are  capable  of  containing  makes  them  seldomer  require 
to  be  filled;  it  is  probable,  likewise,  that  it  is  the  sensation  excited 
by  this  fulness  which  gives  satisfaction  to  the  animal,  and  takes 
off  the  further  desire  for  food,  an  effect  similar  to  what  is  pro- 
duced in  other  animals  from  filling  the  stomach  itself ; and  these 
having  no  such  provision,  are  longer  and  oftener  employed  in  pursuit 
of  food. 

I should  be  apt  to  consider  the  power  of  the  gastric  juice  to 
coagulate  milk,  and  some  other  animal  mucilages,!  as  a test  of  the 
stomach  being  the  seat  of  digestion ; for  although  milk  may  be 
coagulated  by  other  substances,  yet  when  found  in  that  state  in  the 
stomach  it  is  probably  for  the  purpose  of  digestion,  milk  and  many 
other  natural  substances  requiring  to  be  coagulated  before  they  can 
be  digested.  I have  found  this  coagulating  power  in  the  stomach 
of  every  animal  that  I have  examined  for  that  purpose,  from  the 
most  perfect  down  to  reptiles and  in  the  appendages  which  I have 

* [According  to  this  difference  in  their  functions,  we  find  that  the  crop  of  the 
eagle  is  relatively  smaller  than  that  of  the  fowl,  and  the  passao-e  of  its  contents  to 
the  stomach  is  more  direct  and  easy.  The  first  stomach  of  the  porpus  is  still 
smaller  in  comparison  with  the  rumen  of  the  sheep  ; and  besides  acting  as  a 
storehouse  for  the  food,  digestion  goes  on  in  it  to  a considerable  extent.  This  is 
effected,  not  by  secretion  from  its  own  parietes,  which,  as  Hunter  observes,  are 
lined  with  a cuticle,  but  most  probably  by  the  gastric  juice  regurgitated  into  it 
from  the  second  stomach,  which  is  highly  glandular.  The  flesh  of  fish  is  found 
separated  from  the  bones,  and  these  in  different  stages  of  softening,  in  the  first 
stomach  ; indeed,  the  construction  of  the  aperture  of  communication  between  the 
first  and  second  stomachs  of  the  porpus  is  such,  that  food  can  pass  into  the 
latter  only  in  a very  comminuted  state.] 

f Milk  is  the  substance  commonly  known  to  be  coagulated  by  the  gastric  juice  ; 
but  I find  that  it  has  also  the  same  power  over  the  white  of  an  egg.  Give  to  a 
dog  some  raw  egg,  and  kill  him  half  an  hour  after  he  has  swallowed  it,  the  egg 
will  be  found  coagulated  in  his  stomach,  as  if  boiled.  The  crystalline  humour 
in  the  stomachs  of  fishes  is  likewise  found  coagulated. 

j;  [By  “ reptiles  ” there  is  reason  to  believe  Mr.  Hunter  meant  ‘ creeping  things,’ 
as  insects  and  worms.  The  ‘ Reptilia  ’ of  modern  naturalists  he  invariably  calls 
by  the  Linnsean  nam'e  ‘Amphibia,’  or  by  his  own  term,  ‘Tricoilia.’  In  the  In- 
troduction to  the  Series  of  Digestive  Organs,  (Phys.  Catalogue  of  the  Hunterian 
Collection,  vol.  i.)  he  says,  “ In  some  reptiles  the  teeth  are  placed  in  the  (esopha- 
gus,” alluding  to  preparations  of  a Nereis;  and  in  a manuscript,  published  in 

13 


134 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


considered  as  only  reservoirs  preparatory  to  digestion,  (as  the  first 
stomach  in  the  ruminating  animal,  and  the  crop  in  birds,)  1 have 
discovered  no  such  power.  Yet  it  is  not  the  digestive  power  which 
coagulates  those  substances,  complete  coagulation  taking  place  even 
where  digestion  does  not  at  all  go  on.*  This  is  evident  every  day 
in  children  who  suck,  and  who  have  diseased  stomachs;  for  we  see 
them  throw  up  the  milk  coagulated,  and  discharge  it  undigested  by 
stool.  A very  remarkable  instance  occurred  in  a child  that  had 
lost  entirely  the  power  of  digestion,  yet  the  milk  taken  down  came 
away  strongly  coagulated,  some  even  as  firm  almost  as  cheese; 
which  seems  to  show  that  the  coagulating  power  is  seldom  wanting, 
although  the  other  may. 

The  gastric  juice  is  a fluid  somewhat  transparent,  and  a little 
saltish  or  brackish  to  the  taste;  but  whether  this,  is  essential  or  only 
accidental  is  not  easily  determined.  Indeed  there  are  very  few  of 
our  secretions  which  have  not  some  salt  in  them  ; it  being  found  in 
the  tears,  the  saliva,  the  secretion  of  the  glans  penis,  of  the  glands 
of  the  urethra,  and  in  the  first  and  the  last  milk  secreted  in  the 
udders  of  animals. 

I am  not  inclined  to  suppose  that  there  is  any  acid  in  the  gastric 
juice  as  a component  or  essential  part  of  it,  although  an  acid  is  very 
commonly  discovered,  even  when  no  vegetable  matter  has  been  in- 
troduced into  the  stomach.f  The  acid  may  be  increased  in  some 

the  same  volume  of  the  Physiological  Catalogue,  there  is  proof  that  he  experi- 
mented on  an  insect  with  especial  reference  to  the  seat  of  the  digestive  power. 
After  detailing  the  peculiarities  of  the  digestive  organs  in  the  flesh-fly  [Musca 
vomitoria),  he  observes : 

“ The  bag  belonging  to  the  first-described  canal  is  to  be  considered  a craw  or 
crop,  viz.,  a reservoir  for  the  food  to  be  ready  for  digestion  ; and  as  the  abdomen 
contains  almost  every  internal  part  of  ibe  animal,  it  is  obliged  to  be  situated  in 
this  cavity.  That  it  is  a reservoir  for  food  I proved  by  experiment;  I kept  some 
of  these  flies  fasting  for  some  time:  1 then  gave  them  milk,  which  they  drank 
readily;  and  when  I thought  they  had  filled  their  bellies,  I put  them  into  spirits, 
which  assisted  in  coagulating  the  milk  wherever  it  might  be.  On  opening  the 
abdomen,  I found  this  bag  full  of  curd  and  whey,  as  also  some  in  the  stomach. 
I kept  a fly  for  twelve  hours  without  food,  and  then  gave  it  milk,  and  killed  it, 
and  found  no  milk  in  the  crop,  but  it  had  got  through  almost  the  whole  tract  of 
intestines  : here  the  animal  had  immediate  occasion  for  food,  therefore  the  milk 
did  not  go  into  the  crop.  This  experiment  at  the  same  time  shows  that,  probably, 
every  part  of  the  intestines  digest,  for  the  stomach  makes  no  distinct  bag.”] 

* [Or  ratber  the  digestive  power  may  be  equal  to  the  coagulation,  but  not  to 
the  completion  of  the  digestion  of  the  coagnlable  substances.] 

f The  only  trial  to  which  I ever  put  the  gastric  juice  was  with  the  syrup  of 
violets,  to  ascertain  if  it  was  acid  ; and  in  many  of  the  trials  the  colour  of  the 
mixture  was  changed  to  red.  But  it  is  necessary,  for  the  accuracy  of  the  experi- 
ment which  is  to  determine  this  fact,  that  the  animal  should  not  be  fed  upon 
vegetables  for  some  time  before  the  trial  is  made,  these  being  liable  in  some  de- 
gree to  become  sour;  therefore  it  is  hardly  fair  to  make  the  experiment  on  the 
contents  of  the  stomach  of  animals  who  live  upon  vegetables.  In  many  trials  of 
this  kind  we  may  be  deceived,  and  led  to  suppose  an  alkali ; for  certain  animal 
secretions  being  of  a yellow  cast,  when  sucb  are  mixed  with  the  syrup  of  violets 
the  mixture  is  changed  to  a green.  The  truth  of  the  experiment  may,  however, 
be  known  by  adding  a little  acid  ; for  if  the  green  has  been  produced  merely  by 


OBSERVATIONS  ON  DIGESTION. 


135 


diseases,  and  in  others  the  disposition  to  form  it  may  be  destroyed, 
which  may  be  the  reason  why,  by  a kind  of  instinctive  principle, 
many  girls  are  fond  of  eating  sour  fruit  and  of  drinking  vinegar; 
while  others,  on  the  contrary,  from  a different  cause,  often  eat  chalk, 
lime,  and  other  substances  of  that  sort.  But  the  acid  not  being 
always  found,  it  is  not  yet  determined  on  what  occasions  it  is  formed, 
or  in  what  manner  it  is  destroyed. 

The  process  of  digestion  dilfers  from  every  other  natural  opera- 
tion in  the  change  it  produces  on  different  bodies  ; yet  it  is  by  no 
means  fermentation,  though  it  may  somewhat  .resemble  it.  For 
fermentation,  a spontaneous  process,  is  that  natural  succession 
of  changes  by  which  vegetable  and  animal  matter  is  reduced  to 
earth ; therefore  must  be  widely  different  from  digestion,  which 
converts  both  animal  and  vegetable  substances  into  chyle,  in  the 
formation  of  which  there  cannot  be  a decomposition  similar  to  fer- 
mentation. 

Digestion  is  likewise  very  different  from  chemical  solution,  which 
is  only  a union  of  bodies  by  elective  attraction.  But  digestion  is 
an  assimilating  process ; and  in  this  respect  is  somewhat  similar 
in  its  action  to  that  excited  by  morbid  poisons.  It  is  a species  of 
generation,  two  substances  making  a third;  but  the  curious  cir- 
cumstance is  its  convertin<T  both  vegetable  and  animal  matter  into 
the  same  kind  of  substance  or  .compound,  which  no  chemical  pro- 
cess can  effect.  The  chyle  is  compounded  of  the  gastric  juice 

a mechanical  mixture,  it  will  become  immediately  a scarlet,  by  being  then  a mix- 
ture of  red  and  yellow  ; but  if  the  secretion  is  not  only  of  a yellow  colour,  but 
of  an  alkaline  nature,  it  will  also  continue  green;  and  by  adding  a little  more 
acid  than  what  saturates  the  alkali  the  colour  will  then  become  orange. 


“ [Various  opinions  have  been  entertained  as  to  the  acidity  of  the  gastric  juice. 
Spallanzani  believed  it  to  be  a neutral  fluid.  Carminati  could  detect  no  acid  in 
the  gastric  juice  of  carnivorous  animals  and  mixed  feeders,  but  found  it  to  exist 
in  that  of  vegetable  feeders.  {Utbtr  die  Natur  des  Magensaftes,  Wien,  1785.) 
Helm,  who  examined  the  gastric  juice  in  a patient  with  a fistulous  opening  in  the 
stomach,  also  states  that  it  contains  no  sensible  acid.  {Ttwei  Krankengeschicten, 
Wien,  1803.)  The  same  cause  of  error  has  probably  operated  in  each  of  the  pre- 
ceding cases,  viz.,  not  making  a sufficient  distinction  between  the  ordinary 
mucous  secretion  of  the  stomach  and  the  peculiar  fluid  which  is  poured  out  from 
the  stimulus  of  the  contact  of  food,  or  any  innutritions  substances.  In  the  experi- 
ments of  Tiedemann  and  Gmelin  the  ordinary  secretion  of  the  stomach  in  fasting 
horses  and  dogs  was  found  to  be  almost  neutral,  or  very  slightly  acid  ; but  on 
stimulating  the  surface  by  means  of  stones,  (by  which  any  cause  of  error  from 
a change  of  fermentable  substances,  as  alluded  to  by  Hunter,  was  avoided,)  then 
the  secretion  manifested  unequivocally  the  presence  of  acidity.  Beaumont  has 
more  fully  established  the  acidity  of  the  gastric  juice  in  the  work  before  quoted. 
He  observed  in  the  man  with  gastric  fistula  that  the  gastric  juice  was  poured  out 
from  numerous  minute  clear  points  or  papilla;.  1;  is  a clear  inodorous  fluid,  with 
a somewhat  salt  and  very  marked  acid  taste,  like  that  of  thin  mucilage  which 
has  been  soured  with  muriatic  acid.  It  dissolves  in  water,  wine,  and  alcohol ; 
slightly  effervesces  with  alkali;  decomposes  slowly,  and  retards  the  decomposi- 
tion of  animal  matter.  Saliva  imparts  to  the  gastric  juice  a blue  colour  and  a 
frothy  appearance.  Chemical  analysis  show's  the  gastric  juice  to  contain  both 
the  muriatic  and  acetic  acids,  alkaline  phosphates,  muriate  of  soda,  magnesia,  and 
lime,  and  an  animal  matter  which  is  soluble  in  cold  but  not  in  hot  water,] 


136 


HUNTER  ON  THE  ANIMAL  OGCONOMY. 


and  digestible  substances  when  perfectly  converted  ; and  it  is  pro- 
bable that  the  quantity  of  gastric  juice  may  be  nearly  equal  to  that 
part  of  the  food  which  is  really  changed  into  chyle.  If  so,  it 
demonstrates  the  necessity  of  a very  quick  secretion,  to  supply  a 
quantity  so  very  considerable;  but  with  this  advantage,  that  it  is 
not  lost  to  the  constitution. 

The  progress  of  the  conversion  of  food  into  chyle  may  be  often 
seen  in  the  stomach  of  animals  at  different  times  after  feeding. 
Fishes  are  good  subjects  on  which  to  make  observations  for  this 
purpose,  as  they  swallow  their  food  whole;  and  as  "that  food  is 
commonly  fish,  and  often  too  large  to  be  completely  admitted  into 
the  stomach.  As  they  do  not  masticate  their  food,  it  is,  not  adapted 
to  the  cavity  of  the  stomach  ; and  therefore  part  of  it  is  often  found 
lying  in  the  oesophagus;  a circumstance  by  which  the  comparative 
progress  of  digestion  is  rendered  more  obvious. 

It  may  also  be  well  observed  in  the  stomach  of  a dog,  in  which 
the  whole  quantity  taken  has  been  swallowed  at  once.  In  the  great 
end  the  food  will  be  but  little  altered ; towards  the  middle,  more ; 
and  towards  the  pylorus  it  will  be  similar  to  what  is  found  in  the 
duodenum.* 

From  the  structure  of  the  stomach  in  ruminating  animals  they 
are  badly  adapted  to  assist  our  inquiries  on  this  subject,  because 
metallic  balls,  or  whatever  is  swallowed  in  so  hard  and  solid  a 
form  as  to  be  unfit  for  digestion,  requiring  to  be  ruminated,  will 
often  be  thrown  out  when  returned  into  the  mouth  for  that  pur- 
pose; or  it  may  lie  a long  time  in  the  first  'stomach  without  being 
either  thrown  up  or  passed  into  the  fourth,  as  I have  frequently 
seen;  therefore  the  chance  of  its  getting  into  the  fourth  stomach 
in  a proper  time  to  fit  it  for  the  object  of  an  experiment  being  very 
uncertain,  no  great  light  can  be  derived  from  trials  made  on  animals 
of  this  class. 

Live  or  fresh  vegetables,  when  taken  into  the  stomach,  are  first 
killed,  by  which  a fiabbiness  in  their  texture  is  produced,  as  if  they 
had  been  boiled ; and  then  they  can  be  acted  upon  by  the  gastric 
juice. 

Meat  appears  to  undergo  no  change  as  preparatory  to  digestion, 
but  at  once  to  submit  to  its  union  with  the  gastric  juice  ; for,  after 
having  been  acted  upon,  it  seems  first  to  lose  its  texture,  then  be- 
comes cineritious  in  colour,  next  gelatinous,  and  last  chyle.  The 
first  change  made  upon  milk  and^some  other  secretions,  as  the  yolk 
and  white  of  an  egg,  is  coagulation;  after  which  the  gastric  juice 
begins  to  acquire  a power  of  uniting  with  them. 

The  first  change  which  is  produced  on  animal  substances  out  of 
the  body,  either  by  being  exposed  to  heat  or  by  becoming  spontane- 

* [The  cardiac  and  pyloric  portions  of  the  stomach  possess  the  digestive  power 
in  very  different  degrees,  it  being  much  more  energetic  in  the  latter.  In  the 
stomachs  of  Carnivora  and  Rodentia  the  two  portions  are  commonly  found  divided 
by,a  constriction;  and  the  same  hour-glass  contraction  of  the  stomach  is  occasion- 
ally met  with  in  the  human  subject.  See  Sir  Everard  Home,  Phil.  Trans.  1817, 
p.  347.] 


OBSERVATIONS  ON  DIGESTION. 


137 


ously  putrid,  is  similar  to  the  second  of  the  three  changes  which 
takes  place  in  digestion ; and  is  only  preparatory  to  the  complete 
change,  whether  that  be  digestion  or  putrefaction. 

It  appears  from  many  experiments  that  the  digested  or  animalized 
part,  when  carried  into  the  intestine,  is  attracted  by  the  villous  coat, 
or  clings  to  it  as  if  entangled  among  the  villi;  while  the  excremen- 
titious  part,  such  as  bile,  is  found  lying  unconnected  in  the  gut,  as 
if  separated  from  the  other.* 

The  food  of  animals  in  general  consists  of  vegetable  or  animal 
substances;  and  vegetables  seem  intended  to  support  one  class, 
with  a view  to  its  being  the  food  of  another.  Although  there  are 
classes  of  animals  intended  to  subsist  on  each  particular  kind  of 
food,  yet  they  do  not  all  invariably  keep  to  the  same  kind  in 
every  stage  of  life,  many  being  nourished  by  animal  food  when 
young  that  afterwards  live  on  vegetables  ; which  circumstance  will 
be  more  fully  discussed  while  treating  of  the  first  food  of  pigeons. 

All  stomachs  do  not  equally  digest  the  same  substance,  although 
it  be  their  natural  food.  The  caterpillar  digests  the  expressed  juice, 
but  not  the  substance;  w'hile  other  animals  are  capable  of  dissolving 
nearly  the  whole.  Some  animals,  as  the  common  cattle,  can  feed 
on  a variety  of  vegetables,  although  they  may  have  a preference  ; 
but  there  are  others  that  will  hardly  eat  of  more  than  one  kind. 
Of  this  last  sort  are  insects  in  general,  and  the  silkworm  will 
scarcely  touch  anything  but  mulberry  leaves ; but  I believe  those 
that  live  upon  animal  food  are  not  so  restricted  in  'their  choice. 

It  is  probable  that  all  animal  and  vegetable  substances  are  equally 
capable  of  being  digested,  if  equally  soft  in  their  texture;  but  some 
being  much  firmer  in  that  respect,  and  others  also  united  with  in- 
digestible matter,  as  the  earth  in  bones,  more  strongly  resist  the 
powers  of  the  gastric  juice  ; therefore  mastication  and  trituration 
become  necessary  to  bring  them  to  a similar  consistence.  But  sub- 
stances may  be  rendered  too  soft,  for  a fluid  is  difficult  of  digestion  ; 
and  we  may  observe,  that  Nature  having  given  us  very  few  fluids 
as  articles  of  food,  to  render  these  few  fitter  for  the  action  of  the 
digestive  powers,  a coagulating  principle  is  provided  to  give  them 
some  degree  of  solidity. f It  is  not  easy  to  assign  a reason  why 

* [In  cliylifioation,  the  alkaline  principles  of  thrt  bile  combine  with  the  acids 
which  the  chyme  has  received  in  its  formation  in  the  stomach,  and  tge  albumi- 
nous or  chylous  principles  are  developed  and  attracted  by  the  villi ; while  the 
resinous  parts  of  the  bile,  combined  with  the  excrementitions  'particles  of  the 
chyme,  are  more  or  less  completely  separated.  The  most  characteristic  change 
which,  according  to  Prout,  takes  place  in  the  intestine  is  tlie  conversion  of  part 
of  the  chyme  into  albumen,  which  happens  even  when  no  albuminous  matter  was 
originally  contained  in  the  food  or  formed  in  the  stomach.] 

f The  circumstance  of  the  crystalline  humour,  which  is  solid,  being  coagulated 
prior  to  its  being  digested,  renders  it  probable  that  all  animal  substances  ga 
through  that  process,  and  that  the  loss  of  texture  which  they  undeigo  arises 
from  coagulation. a 


3-  [This  coagulation  happens  to  all  animal  substances  which  contain  albumen; 
hut  can  hardly  be  considered,  Dr.  Prout  observes,  “ to  be  essential  to  the  subse- 

13* 


138 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


fluidity  should  be  unfavourable  to  the  process  of  digestion,  more 
especially  as  it  seems  essential  to  those  of  fermentation  and  chemi- 
cal solution.  The  requisite  degree  of  solidity  1 should  suppose  to 
be  that  of  curd,  or  what  is  produced  by  the  coagulation  of  animal 
mucilages,  as  of  the  white  of  an  egg.  But  this  is  only  supposition, 
founded  on  the  idea'  that  Nature’s  general  principles  are  right,  and 
all  the  corresponding  parts  adapted  to  one  another,  except  when 
monstrous,  either  in  form  or  action. 

Mastication  is  the  efl'ect  of  a mechanical  power,  produced  by 
parts  particularly  provided  for  that  purpose,  which  are  of  various 
kinds,  fitted  for  that  sort  of  food  on  which  the  animal  is  by  Nature 
intended  to  live,  and  may  be  imitated  with  equal  advantage  by  many 
other  pieces  of  meclianism. 

The  masticating  powers  are  of  three  kinds.  The  first  is  that 
which  merely  fits  the.  substance  for  deglutition,  as  in  the  lion  and 
many  other  carnivorous  animals  ; and  which,  in  the  ruminating 
tribe,  renders  the  food  fit  to  be  swallowed,  that  it  may  undergo  such 
preparation  in  the  first  stomach  as  is  necessary  before  it  is  further 
masticated  for  digestion.  The  second  is  that  which  not  only  fits 
the  food  for  deglutition,  but  exposes  it  ,to  the  action  of  the  gastric 
juice,  by  breaking  the  shells  or  husks  in  which  the  nourishment  is 
contained,  and  in  which  it  would  be  defended  from  the  powers  of. 
digestion.  And  the  third  is  that  which  divides  and  bruises  the  food 
before  it  is  received  into  the  stomach  ; which  mastication  is  of  con- 
siderable service,  by  producing  a saving  in  food.* 

The  husk  of  the  seeds  of  plants,  although  a vegetable  ' substance, 
appears  to  be  indigestible  in  its  natural  slate.  Whether  this  arises 
from  the  nature  of  the  husk  itself,  or  from  its  compactness,  I am 
not  quite  certain,  but  am  inclined  to  suppose  the  last,  as  we  find  the 
cocoa,  which  is  only  a husk,  to  be  digestible-  when  ground  to  a 
powder  and  well  boiled.  We  know  likewise  that  cuticle,  horn,  hair, 
and  feathers,  although  animal  substances,  are  not  affected,  in  the 
first  instance,  by  the  gastric  juice ; yet  if  reduced  in  Papin’s  digester 
to  a jelly,  that  jelly  can  be  acted  upon  in  the  stomach:  we  must 
therefore  suppose  that  a certain  natural  degree  of  solidity  in  animal 
and  vegetable  substances  renders  them  indigestible.  This  com- 
pactness in  the  husk  seems  to  be  intended  to  preserve,  while  under 
ground,  the  farinaceous  part  of  the  seed,  in  which  the  living  principle 
is  placed,  the  husk  having  probably  no  other  power  of  resisting 
putrefaction  than  what  arises  from  its  texture;  but  whatever  may 
be  the  use  of  the  husk,  it  must  be.  connected  witji  the  vegetative 
process  .of  .the  plant,  The  same  purpose  of  preservation  is  pro- 
bably answered  by  The  shells  of  all  ova.  Although  husks  are  not 
capable  of  being  dissolved  in  the  gastric  juice,  they  allow  of  transu- 
dation, and  that  the  seed  is  in  some  degree  affected  by  it  is  known 

quent  process,;  for  gelatin,  a staminal  alimentary  principle,  nearly  resembling 
albumen  in  its  composition,  undergoes,  under  similar  circumstances,  no  such 
solidifying  change.  (Br.  Tr.,  p'494.)] 

* [Bluinenbach  has  well  suggested  .that  the  vitality  of  the  seeds  is  thus  de- 
stroyed and  they  are  made  subject  to  the  influence  of  the  gastric  juice.] 


OBSERVATIONS  ON  DIGESTION. 


139 


by  its  swelling  in  the  stonaach;  yet  it  can  only  take  up  a certain 
proportion  of  it,  and  that  not  sufficient  to  convert  it  into  chyle,  the 
gastric  juice  having  no  power  of  action  upon  the  husks  themselves. 
Therefore  we  see  grain  of  all  kinds,  when  swallow'ed  whole,  pass 
through  entire,  though  swelled  ; and  even  the  kernels  of  some  nuts, 
as  chestnuts,  are  not  digestible  when  eaten  raw. 

The  essential  oils  of  vegetables  and  animals  are  indigestible;  but 
being  soluble  either  in  the  gastric  juice  or  chyle,  they  become 
medicinal,  from  their  stimulating  powers.  The  essential  oil  of 
vegetables,  but  more  particularly  that  of  animals,  seems  to  pervade 
the  very  substance  of  those  animals  whose  food  contains  much  of 
this  oil.  Thus,  we  find  sea-birds,  whose  constant  food  is  fish,  taste 
very  strongly  offish;  and  those  who  live  on  that  kind  of  food  only 
during  certain  times  of  the  year,  as  the  wild  duck,  have  that  taste 
only  at  such  seasons.  This  fact  is  so  well  known  that  it  was 
hardly  necessary  to  put  it  to  the  test  of  an  experiment;  yet  I took 
Two  ducks,  and  fed  one  with  barley,  the  other  with  sprats,  for  about 
a month,  and  killed  both  at  the  same  time  : when  they  were  dressed, 
the  one  fed  wholly  with  sprats  was  hardly  eatable,  it  tasted  so  strongly 
of  fish. 

Although  bones  are  in  part  composed  of  animal  substance,  and 
so  far  digestible,  yet  they  require  stronger  powers  to  digest  them 
than  common  meat,  from  the  animal  substance  being  guarded  by 
the  earth.  Thus,  the  animal  part  of  a bone  is  less  easily  soluble  in 
an  alkali  than  flesh,  or  than  even  the  animal  part  when  deprived  of 
its  earth  by  an  acid;  nor  will  a bone,  being  guarded  by  the  calcare- 
ous earth,  submit  to  putrefaction  so  readily  as  meat ; therefore 
animals  which  live  upon  others,  and  swallow  them  wdiole  as  the 
heron,  digest  bone  with  more  ease  than  the  crow  or  magpie,  that  are 
not  accustomed  to  swallow  bones,  but  commonly  pick  the  flesh  only. 

The  degree  of  ease  or  difficulty  with  which  substances  are 
digested,  will  not  only  arise  from  a difference  in  solidity,  but 
from  a difference  in  the  structure  of  the  parts  themselves  ; brain, 
liver,  muscle,  and  tendon,  being  digestible  in  the  order  here  put 
down. 

There  is  not  only  a difference  in  the  degree  of  facility  with  w'hich 
the  various  kinds  of  natural  food  are  digested,  but  these  can  also 
be  made  to  undergo  changes  by  art,  which  render  them  still  more 
easy  ol  digestion;  for  it  appears  froin  my  experiments  that  boiled 
and  roasted,  and  even  putrid  meat,  is  easier  of  digestion  than  raw, 
which,  in  the  two  first,  may  be  supposed  to  arise  from,  their  juices 
being  coagulated;  but  the  same  reason  will  not  hold  good  with’ 
regard  to  the  putrid.^  A raw  egg  is  thought  more  easy  of  diges- 

* [From  the  various  experiments  instituted  by  Sir  Astlpy  Cooper  on  the  diges- 
tibility of  ditferent  substances,  it  appears  that  pork  is  more  digestible  than  mutton, 
this  than  veal,  while  beef  is  the  least  digestible  of  any.  In  feeding  dogs  with 
determinate  quantities  of  each,  and  opening  them  at  the  expiration  of  a given 
period,  it  happened  that  in  some  instances  the  pork  and  mutton  had  entirely  dis- 
appeared, while  the  beef  remained  but  little  altered.  Fish  and  cheese  were  also 
found  to  be  very  digestible  substances.  Potatoes  were  digestible  in  a less  degree: 


140 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


tioii  than  an  egg  hard  boiled,  although  the  raw  one  must  be  coagu- 
lated in  the  stomach  before  it  can  be  digested ; and  it  has  likewise 
been  observed,  that  what  is  easy  of  digestion  is  one  stomach  will 
not  be  so  in  another ; but  such  cases  may  probably  arise  from  the 
stomach  not  being  in  a healthy  state. 

In  many  animals  the  whole  of  the  food  does  not  appear  to  be 
digested,  the  substance  in  part  being  found  in  the  faeces  ; for  if  a 
dog  is  fed  with  tallow,  his  excrements  will  consist  of  a somewhat 
firm  unctuous  substance,  so  that  the  oil  is  only  digested  in  part. 
The  circumstance  of  some  part  of  the  food,  though  digestible,  not 
being  acted  upon  by  the  gastric  juice',  may  arise  from  two  causes: 
first,  from  many  parts  of  vegetables  being  too  firnvin  texture  to  be 
digested  in  the  same  time  with  the  other  food,  and  being  therefore 
carried  along  in  a crude  state,  together  with  the  chyle,  into  the 
duodenum  ; and  secondly,  from  the  stomach  at  the  time  being  so 
much  disordered  as  to  digest  imperfectly.  We  know  that  food  may 
lie  a considerable  time  in  the  stomach  when  it  is  diseased  withoui 
being  digested.  Food  has  been  retained  in  the  stomach  twenty-four 
hours,  and  throwm  up  without  being  in  the  least  altered,  the  animal 
at  the  time  not  requiring  nourishment : this  often  arises  from  disease, 
and  is  also  the  case  with  those  which  go  to  rest  in  the  winter. 

The  powers  of  digestion  may  in  some  instances  be  estimated  by 
the  appearance  of  the  excrement,  in  which,  if  the  food  appears  not 
to  be  much  altered,  we  may  conclude  that  digestion  has  had  little 
or  410  influence  on  it.  Thus,  the  excrement  of  a flea,  that  has  lived 
on  blood,  is  nearly,  to  appearance,  pure  blood,  not  having  even  lost 
its  colour. 

Animals  take  food  in  proportion  to  the  quantity  of  nourishment 
contained  in  it,  of  which  the  stomach  appears,  from  instinct,  to  be 
capable  of  judging;  and  also  in  proportion  to  the  powers  they  pos- 
sess of  converting  what  they  eat  into  chyle,  A caterpillar,  perhaps, 
eats  more  in  proportion  to  its  size  than  any  other  animal  that  lives 
on  the  same  kind  of  food  ; for  not  having  the  power  of  dissolving 
the  v'egetable,  but  only  of  extracting  a juice  or  infusion  from  it,  the 
bit  of  leaf  comes  away  entire,  coiled  up  and  hardened  ; but,  by 
being  put  into  water,  unfolds  like  tea. 

There  are  few  animals  that  dp  not  eat  flesh  in  some  form  or 
other,  while  there  are  many  'who  do  not  eat  vegetables  at  all ; and 
therefore  the  difficulty  to  make  the  herbivorous  eat  meat  is  not  so 
great  as  to  make  the  carnivorous  eat  vegetables.  Where  there  is 
an  instinctive  principle  in  an  animal,  directing  it  either  to  the  one 
species  of  food  or  the  other,  the  animal  will  certaintly  die  rather  than 
break  through  of  its  own  accord  that  natural  law  ; but  it  may  be 
made  to  violate  every  natural  principle  by  artificial  means.  That 
the  hawk  tribe  can  be  made  to  feed  upon  bread,  I have  known  these 
thirty  years;  for  to  a tame  kite  I first  gave  fat,  which  it  ate  very 
readily;  then  tallow  and  butter;  and  afterwards  small  balls  of 

Boiled  veal  was  found  to  be  two-thirds  more  digested  than  the  same  meat  roasted^ 
&c.  Muscular  tissue,  skin,  gristle,  tendons,  bone,  were  digestible  in  the  order 
here  set  down.] 


OBSERVATIONS  ON  DIGESTION. 


141 


bread  rolled  in  fat  or  butter,  and  by  decreasing  the  fat  gradually, 
it  at  last  ate  bread  alone,  and  seemed  to  thrive  as  well  as  when 
fed  with  meat.  This,  however,  produced  a diflerence  in  the 
consistence  of  the  excrements,  for  when  it  ate  meat  they  were 
thin,  and  it  had  the  power  of  throwing  them  to  some  distance  ; but 
when  it  ate  bread  they  became  firmer  in  texture,  and  dropped  like 
excrement  of  a common  fowl.  Spallanzani  attempted,  in  vain,  to 
make  an  eagle  eat  bread  by  itself;  but  by  inclosing  the  bread  in 
meat,  so  as  to  deceive  the  eagle,  the  bread  was  swallowed,  and 
digested  in  the  stomach. 

The  excrements  of  animals  we  may  suppose  to  be  that  part  of 
the  common  food  which  is  indigestible  ; and  as  food  is  either  animal 
or  vegetable,  and  each  different  kind  adapted  to  distinct  classes  of 
animals,  it  is  natural  to  believe  that  the  excremeirtitious  part  of 
each  will  be  different’;  and  where  the  animal  feeds  upon  both,  that 
the  excrement  will  be  of  a mixed  nature.  Although  this  appears 
probable,  it  is  only  true  in  a certain  degree  ; for  the  mode  of  diges- 
tion, and  whether  the  animal  has  a cascum  and  colon,  with  their 
peculiar  form,  have  all  an  influence  in  the  changes  which  the  food 
undergoes.  Vegetable  food  produces,  more  excrement  than  animal, 
and  this  according  to  the  kind  or  parts  of  vegetables  that  are  eaten. 
The  woody  parts  and  husks,  which  are  indigestible,  produce  the 
most ; the  true  farinaceous  part  the  least : why  there  should  be 
any  at  all  from  the  farinaceous  and  animal  substance,  except  what 
has  eluded  the  action  of  the  digestive  organs,  is  not  easily  ac- 
counted for. 

All  fEeces  have  a tendency  to  putrefaction,  but  least  in  those 
animals  which  feed  on  vegetables.  Indeed,  the  excrement  from 
vegetable  food  alone  could  hardly  ever  become  putrid  if  it  was  not 
mixed  with  the  mucus  of  the  intestines,  and  would  even  then  be 
kept  sweet  by  the  tendency  which  undigested  vegetables  have  to 
take  on  the  vinous  and  acetous  fermentation.  But  the  freces  of 
those  which  live  entirely  on,  animal  food  in  general  very  soon 
become  putrid  ; and  indeed  often  before  they  are  voided  ; but  such 
animals  are  either  without  ctecum  or  colon  ; or  if  not,  what  they 
have  is  very  short ; so  that  the  excrement  not  being  long  retained, 
has  less  time  to  become  putrid.  When  the  feces  stagnate  so  as 
to  take  on  either  the  vinous  or  putrefactive  fermentation,  air  is  let 
^ loose,  which  will  be  according  to  the  nature,  of  the  fermentation  ; 
most  probably,  from  the  vegetable  it  will  be  fixed,  and  from  the 
animal,  inflammable  air. 

The  feces  of  the  greatest  number  of  animals  are  tinged  by  the 
bile,  which  in  some  gives  them  a yellowish-green  colour;  in  the 
bird  they  are  generally  green,  but  sometimes  white,  from  being _ 
mixed  with  the  urine.  The  feces  of  the  maggot  appear  to  be 
loaded  with  bile  ; for  besides  being  yellow,  they  are  extremely 
bitter,  which  is  known  by  eating  the  kernel  of  a nut  that  has  a 
maggot  in  it.  Some  kinds  of  food,  when  not  wholly  digested,  give 
a tinge  to  the  feces,  as  grass  to  the  excrement  of  cows. 


142 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  animals  which  feed  upon  vegetables  alone  commonly  have 
their  faeces  somewhat  solid ; but  the  degree  will  vary  accoi'ding  to 
the  state  of  the  vegetable,  whether  green  or  dried ; and  therefore 
the  particular  state  of  the  faeces  will  depend  on  the  nature  of  the 
indigestible  part  of  the  food,  and  must  be  different  according  to  the 
digestive  powers  in  different  animals.  'An  animal  that  feeds  upon 
grass  has  the  faeces  much  softer  than  when  fed  on  the  same  kind 
of  grass  made  into  hay;  and  therefore  the  fasces  of  the  herbivorous 
animals  are  softer  in  the  summer  than  the  winter ; but  green  vege- 
table food  does  not  produce  soft  faeces  in  all  animals,  for  the  cater- 
pillar, wliich  lives  upon  the  leaves  of  vegetables,  has  its  faeces 
almost  dry;  and  we  find  in  some  ruminating  animals,  as  sheep, 
that  the  difference  in  the  fasces  during  summer  and  winter  is  incon- 
siderable. The  quajjrupeds  and  birds  that  live  principally  upon 
vegetables  generally  have  their  caeca  large  and  the  colon  long,  as 
we  see  in  many  of  thp  ruminating  animals.  Some  have  the  colon 
both  long  and  large,  as  the  horse  and  those  of  the  rat  tribe,  which 
circumstance  has  considerable  effects  in  allowing  the  faeces  to 
become  dry:  in  a few  of  the  ruminating  animals,  and  of  the  rat 
kind,  they  are  formed  into  small  portions. 

The  faeces  of  quadrupeds  living  upon  animal  food  are  commonly 
soft,  and  in  birds  are  fluid  ; but  in  such  as  live  on  both  animals  and 
vegetables,  they  are  in  consistence  of  a mixed  nature,  and  will  be 
more  or  less  soft  according  to  the  food.  If  a dog  is  fed  entirely 
on  animal  substance  its  fasces  will  be  soft ; if  whollyon  vegetable  as  on 
bread,  they  will  become  so  hard  as  to  be  expelled  with  difficulty.* 


* [The  following  differences  were  found  by  Dr.  Prout  in  the  contents  of  the 
rectum  of  dogs  which  had  been  fed  on 


Vegetable  Food. 

Of  a firm  consistence,  and  of  an  olive 
brown  col  our,  inclining  to  yellow.  Smell 
foetid  and  offensive.  Did  not  coagulate 
milk. 

A.  Water;  quantity  not  ascertained. 

B.  Combination  or  mixture  of  altered 
alimentary  substances  in  much  greater 
excess  than  in  the  colon,  with  some 
mucus;  insoluble  in  acetic  acid,  and 
constituting  the  chief  bulk  of  the  fasces. 

C.  Albuminous  matter,  none. 

D.  Biliary  principle,  partly  changed 
to  a perfect  resin. 

E.  Vegetable  gluten  1 none;  but  con- 
tained a principle  soluble  in  acetic  acid, 
and  preoipitable  very  copiously  by  oxa- 
late of  ammonia. 

F.  Insoluble  residuum,  consisting 
chiefly  of  vegetable  fibres  mixed  with 
haiis. 


Animal  Food. 

Consisted  of  firm  scybala,  of  a dark 
brown  colour,  inclining  to  chocolate. 
Smell  very  foetid.  Milk  was  coagulated 
by  the  water  in  which  it  had  been  dif- 
fused. 

A.  Water;  quantity  not  ascertained. 

B.  Combination  or  mixture  of  altered 
alimentary  matters  in  much  greater  ex- 
cess than  in  either  the  colon  or  caecum, 
with  some  mucus ; insoluble  in  acetic 
acid,  and  constituting  the  chief  bulk  of 
the  faeces. 

C.  Albuminous  matter,  none. 

D.  Biliary  principle  more  consider- 
able than  in  the  vegetable  faeces,  and 
almost  entirely  changed  to  a perfectly 
resinous-like  substance. 

E.  Vegetable  gluten  I nonejbutcon- 
tained  a principle  soluble  in  acetic  acid, 
and  precipitable  very  copiously  in  oxa- 
late of  ammonia. 

F.  Insoluble  residuum,  consisting 
chiefly  of  hairs.] 


OBSERVATIONS  ON  DIGESTION. 


143 


• Spallanzani  made  some  experiments  to  prove  that  digestion  is 
carried  on  after  death;  but  they  are  not  so  conducted  as  to  corres- 
pond with  the  appearances  met  with  in  the  dead  body  where  that 
process  has  taken  place,  and  the  coats  of  the  stomach  itself  have 
been  in  part  digested.  An  experiment,  although  it  may  be  very 
well  and  accurately  made  so  far  as  the  experiment  goes,  if  a close 
connexion  is  rtot  preserved  with  the  purpose  for  which  it  was  made, 
the  conclusions  to  be  drawn  from  it  cannot  correspond  with  the  in- 
tention. This  is  exactly  tke  case  with  the  experiments  of  Spallan- 
zani, which,  although  they  prove  that  meat  was  digested  in  the 
stomach  after  the  animal  was  killed  (which  no  one  doubted),  yet 
are  not  at  all  calculated  to  show  that  the  stomach  itself  may  be 
digested.  In  fact,  the  mode  in  which  they  were  managed  rather 
tended  to  prevent  that  effect  from  taking  place,,  for  the  gastric  juice, 
by  having  substances  introduced  on  which'  it  could  act,  was  less 
likely  to  aflect  the  coats  of  the  stomach.  That  the  digestion  was 
not  carried  on  merely  by  the  gastric  juice  secreted  before  the 
animal  was  apparently  dead,  is  evident,  from  his  own  account, 
some  of  the  food  which  had  been  introduced  and  digested  being 
found  in  the  duodenum,  a thing  that  could  not  have  happened  if  a 
cessation  of  the  actions  of  life  in  the  involuntary  parts  had  taken 
place  when  visible- life  terminated.  There  had  been  an  action,  and 
most  probably  a secretion,  in  the  stomach.  The  only  experiment 
that  can  be  made  with  any  probability  of  a decided  result,  is  to  kill 
the  animal  while  the  stomach  is  empty,  and  observe  what  after- 
wards takes  place.  There  are  few  stomachs  that  do  not  show, 
when  examined  after  death,  some  of  the  inner  villous  coat  destroyed, 
which  may  have  beep  done  by  the  gastric  juice  in  the  ducts  of  the 
glands  which  secrete  it. 

Dr.  Stevens  in  an  inaugural  dissertation  on  this  subject,  published 
at  Edinburgh  1777,  gives  a number  of  experiments,  some  of  which 
are  well  devised,  to  ascertain  the  substances  that  are'  easiest  of 
digestion,  a thing  in  fact  more  v.'anted  than  the  cause  of  that  pro- 
cess: but  many  of  his  experiments,  more  especially  those  on  rumi- 
nating animals,  were  not  made  with  sufficient  accuracy.  How'  the 
chopped  hay  and  potherbs  came  to  be  so  much  changed  in  the  first 
stomach  of  a ruminating  animal  I cannot  conceive,  as  1 have  reason 
to  believe  it  has  not  the  least  power  of  digesting,  and  should  doubt 
very  much  that  hay  w’as  capable  of  being  wholly  digested  in  any 
stomach.  His  experiment  made  on  substances  out  of  the  body 
proves  that  the  gastric  juice  is  not  able  in  all  cases  to  prevent  the 
vinous  and  acetous  fermentation  in  vegetables,  and  is  a circum- 
stance which  I believe  often  takes  place  in  the  living  body  when  the 
stomach  is  weak.  He  seems  to  be  in  some  apprehension  for  the 
safety  of  the  stomach  itself,  from  the  action  of  so  powerful  a solvent 
as  the  gastric  juice  ; but  though  inclined  to  suppose  that  the  living 
powers  of  the  animal  may  guard  it  against  such  effects,  yet  he  is 
still  disposed  to  fear  that  in  all  cases  they  mav  not  be  sufficient. 

The  living  power  in  the  stomach  must  indeed  be  very  weak  to 


144 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


admit  of  its-  being  digested  ; where  that  was  likely  to  happen,  I 
imagine  the  secretion  of  the  gastric  juice  would  be  too  defective  to 
allow  of  the  stomach  being  acted  upon. 

Dr.  Stevens  gives  two  cases,  with  the  dissections,  to  prove  that 
the  living  stomach  has  not  always  the- power  to  resist  the  action  of 
the  gastric  juice;  but  he  has  not  made  it.  clear  that  those  very 
stomachs  might  not  have  been  digested  after  death.  The  appear- 
ance of  the  edges  of  the  hole  should  have  been  more  particularly 
described  ; for  if  it  look  place  before  death  it  is  probable  it  was 
owing  to  ulceration,  which  I have  sometimes  seen.  Men  should  be 
very  accurate  in  ascertaining  the  truth  of  facts  before  they  advance 
them,  especially  when  they  tend  either  to  overturn  a received  opinion 
or  to  establish  a new  one.  As  to  the  possibility  of  animals  swal- 
lowed alive  being  digested,  no  fresh  'proofs  are  necessary,  as  we 
cat  oysters  every  day;  but  this  does  not  prove  that  they  are  di- 
gested while  alive.  In  his  experiments  made  on  ruminating  animals 
and  the  dog,  as  the  vegetables  -were  not  so  readily  digested  as  the 
meat,  he  concludes,  “ It  is  possible  evei'y  species  of  animal  has  its 
peculiar  gastric-  liquor,  capable  of  dissolving  certain  substances 
only”  which  is  certainly  not  true. 

Mr.  Senebier  relates  some  experiments  made  by  Mr.  Gosse  upon 
himself,  but  which  hardly  contain  anything  except  a curious  con- 
jecture.of  Mr.  Senebier’s,  “That  distention  of  the  stomach  is  the 
cause  of  the  secretion  of  the  gastric  liquor.”  He  mentions  the  sub- 
stances, both  animal  and  vegetable,  which  are  not  digestible:  then 
those  difficult  of  digestion:  afterwards,  those  easily  digested ; also 
what  substances  facilitate  digestion,  and  what  retard  it.  Butif  wm 
are  to  judge  of  the  truth  of  these  facts  from  a detail  of  the  experi- 
ments which  he  made  to  ascertain  them,  I am  quite  inclined  to 
believe  that  the  experiments  have  not  been  made  with  sufficient 
accuracy  to  be  depended  upon. 


11.  ON  THE  DIGESTION  OF  THE  STOMACH  AFTER 

DEATH. 

The  following  account  of  the  stomach  being  digested  after  death 
W’as  drawn  up  at  the  desire  of  the  late  Sir  John  Pringle,  when  he 
was  President  of  the  Royal  Society;  and  the  circumstance  which 
led  to  it  was  as  follows.  I had  opened,  in  his  presence,  the  body 
of  a patient  who  had  been  under  his  care,  in  which  the  stomach 
vvas  found  to  be  in  part  dissolved  ; a thing  that  appeared  to  him 
very  accountable,  there  having  been  no  previous  symptom  which 
could  have  led  him  to  suspect  any  disease  in  the  stomach.  I took 
that  opportunity  of  explaining  to  him  my  ideas  respecting  it ; and 
that,  having  long  been  employed  in  making  experiments  on  digestion, 
I had  been  induced  to  consider  this  as  one  of  the  facts  which  proved 
a converting  power  in  the  gastric  juice.  I mentioned  my  intention 


DIGESTION  OF  THE  STOMACH  AFTER  DEATH. 


14.5 


of  publishing  the  whole  of  my  observations  on  digestion  at  some 
future  period;  but  he  desired  me,  in  the  meantime,  to  give  this  fact 
by  itself,  with  ray  remarks ; as  it  would  prove  that  there  is  a sol- 
vent power  existing  in  the  stomach,  and  would  be  of  use  in  the  ex- 
amination of  dead  bodies.^ 

An  accurate  knowledge  of  the  appearances  in  animal  bodies, 
where  death  has  been  the  consequence  of  some  violence  while  they 
were  otherwise  in  health,  ought  certainly  to  be  considered  as  neces- 
sary to  qualify  us  to  judge  truly  of  the  state  of  the  body  in  those 
that  die  of  diseases.  An  animal  body  undergoes  changes  after 
death;  hut  it  has  never  been  sufficiently  considered  what  those 
changes  are,  or  how  soon  they  may  take  place  ; yet  till  this  be  done 
it  is  impossible  we  can  form  an  accurate  judgment  of  the  appear- 
ances which  present  themselves  at  the  time  of  inspection.  The 
diseases  of  an  animal  body  (mortification  excepted)  are  always 
connected  with  the  living  principle,  and  are  not  in  the  least  similar 
to'  the  changes  which  take  place  in  the  dead  body  : without  a 
knowledge  of  this,  an  opinion  drawn  fi'om  dissections  must  always 
be  very  imperfect  or  very  erroneous.  Appearances  which  are  in 
themselves  natural  may  be  mistaken  for  those  of  disease  ; we  may 
see  diseased  parts,  and  suppose  them  in  a natural  state ; we  may 
consider  a circumstance  to  have  existed  before  death  which  was 
really  a consequence  of  it ; or  we  may  imagine  it  to  be  a natural 
change  after  death,  when  it  was  in  fact  a disease  of  the  living 
body.  It  is  easy  to  see,  therefore,  how  a man  in  this  state  of  igno- 
rance must  blunder  when  he  comes  to  connect  the  appearances  in 
a dead  body  with  the  s5'mptoms  that  were  observed  in  life,;  and, 
indeed,  all  the  advantage  to  be  derived  from  opening  dead  bodies 
depends  upon  the  judgment  and  sagacity  with  which  this  sort  of 
comparison  is  made. 

There  is  a case  of  a mixed  nature,  which  can  neither  be  reckoned 
a process  of  the  living  body  nor  of  the  dead  : it  participates  of  both, 
inasmuch  as  its  cause  arises  from  life,  and  tire  effect  cannot  take 
place  till  after  death.  To  render  this  more  intelligible,  it  will  be 
necessary  to  state  some  general  ideas  concerning  this  cause  and 
effect. 

An  animal  substance,  wdien  joined  with  the  living  principle,  can- 
not undergo  any  change  in  its  properties  but  as  an  animal ; this 
principle  aKvays  acting  and  preserving  the  substance  possessed  of 
it  from  dissolution,  and  from  being  changed  according  to  the 
natural  changes  which  other  substances  undergo. 

[The  original  paper  is  printed  in  the  62d  volume  of  the  Philosophical  Trans- 
actions; and  was  read  June  18th,  1772.  It  begins  as  follows:  “ An  accurate 
knowledge  of  the  appearances  in  animal  bodies  that  die  of  a violent  death,  that 
is,  in’perfect  health,  or  in  a sound  state,  ought  to  be  considered  as  a necessary 
foundation  for  judging  of  the  state  of  the  body  in  those  that  are  diseased.'”  The 
remainder  of  the  essay  is  given  in  the  2d  edition  of  the  Animal  CEconomy,  with 
verbal  alterations  of  the  same  kind  and  degree  as  are  exemplilied  in  the  paragraph 
above  quoted  ; with  the  omission  of  one  sentence  and  a note,  which  are  subjoined 
at  the  end  of  the  paper.] 


14 


146 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


There  are  a great  many  powers  in  nature  which  the  living  prin- 
ciple does  not  enable  the  animal  matter,  with  which  it  is  combined, 
to  resist,  viz.,  the  mechanical  and  most  of  the  strongest  chemical 
solvents.  It  renders  it,  however,  capable  of  resisting  the  powers 
of  fermentation,  digestion,  (and  perhaps  several  others,)  which  are 
well  known  to  act  on  this  same  matter,  and  entirely  to  decompose 
it,  when  deprived  of  the  living  principle.  The  number  of  powers 
which  thus  act  differently  on  the  living  and  dead  animal  substance 
not  being  ascertained,  we  shall  only  take  notice  of  two,  putrefac- 
tion and  digestion,  which  do  not  affect  this  substance,  unless  when 
it  is  deprived  of  the  living  principle.  Putrefaction  is  an  eflect  which 
arises  spontaneously ; digestion  is  an  effect  of  another  principle, 
and  shall  here  be  considered  a little  more  particularly. 

Animals,  or  parts  of  animals,  possessed  of  the  living  principle, 
when  taken  into  the  stomach,  are  not  in  the  least  affected  by  the 
powers  of  that  viscus  so  long  as  the  animal  principle  remains. 
Hence  it  is  that  we  find  animals  of  various  kinds  not  only  can  live 
in  the  stomach,  but  are  even  hatched  and  bred  there;  yet  the 
moment  that  any  of  these  lose  the  living  principle,  they  become 
subject  to  the  digestive  powers  of  the  stomach.  If  it  were  possible 
for  a man’s  hand,  for  example,  to  be  introduced  into  the  stomach 
of  a living  animal,  and  kept  there  for  some  considerable  time,  it 
would  be  found  that  the  dissolvent  powers  of  the  stomach  could 
have  no  effect  upon  it ; but  if  the  same  hand  were  separated  from 
the  body,  and  introduced  into  the  same  stomach,  we  should  then 
find  that  the  stomach  could  immediately  act  upon  it.  Indeed,  if 
the  first  wmre  not  the  case,  the  stomach  itself  ought  to  have  been 
made  of  indigestible  materials  ; for  were  not  the  living  principle 
capable  of  preserving  animal  substances  from  being  acted  upon  by 
the  process  of  digestion,  the  stomach  itself  w'ould  be  digested  ; and 
accordingly  we  find  that  the  stomach,  which  at  one  instant,  that  is, 
w'hile  possessed  of  the  living  principle,  w'as  capable  of  resisting  the 
digestive  powers  which  it  contained,  the  next  moment,  viz.,  w'hen 
deprived  of  the  living  principle,  is  itself  capable  of  being  digested, 
not  only  by  the  digestive  powers  of  other  stomachs,  but  even  by 
the  remains  of  that  power  which  itself  had  of  digesting  other  things. 

These  observations  lead  us  to  account  for  an  appearance  which 
we  often  find  in  the  stomachs  of  dead  bodies ; and  they  at  the  same 
time  throw  considerable  light  upon  the  nature  of  digestion.  The 
appearance  we  allude  to  is  a'dissolution  of  the  stomach  at  its  great 
extremity,  in  consequence  of  which  there  is  frequently  a considera- 
ble aperture  made  in  that  viscus.  The  edges  of  this  opening 
appear  to  be  half  dissolved,  very  much  like  that  kind  of  solution 
which  fleshy  parts  undergo  when  half  digested  in  a living  stomach, 
or  when  acted  upon  by  a caustic  alkali,  viz.,  pulpy,  tender  and 
ragged. 

In  these  cases  the  contents  of  the  stomach  are  generally  found 
loose  in  the  cavity  of  the  abdomen,  about  the  spleen  and  diaphragm  ; 
and  in  many  subjects  the  influence  of  this  digestive  power  extends 


DIGESTION  OF  THE  STOMACH  AFTER  DEATH, 


147 


much  further  than  through  the  stomach.  I have  often  found  that, 
after  the  stomach  had  been  dissolved  at  the  usual  place,  its  contents 
let  loose  had  come  into  contact  with  the  spleen  and  diaphragm,  had 
dissolved  the  diaphragm  quite  through,  and  had  partly  affected  the 
adjacent  side  of  the  spleen,  so  that  what  had  been  contained  in  the 
stomach  was  found  in  the  cavity  of  the  thorax,  and  had  even 
affected  the  lungs  to  a small  degree. 

There  are  very  few  dead  bodies  in  w'hich  the  stomach  at  its  great 
end  is  not  in  some  degree  digested ; and  one  who  is  acquainted 
with  dissections  can  easily  trace  these  gradations.  To  be  sensible 
of  this  effect  nothing  more  is  necessary  than  to  compare  the  inner 
surface  of  the  great  end  of  the  stomach  with  any  other  part  of  its 
inner  surface:  the  sound  portions  will  appear  soft,  spongy,  and 
granulated,  and  without  distinct  blood-vessels,  opake  and  thick ; 
while  the  others  will  appear  smooth,  thin,  and  more  transparent ; 
and  the  vessels  will  be  seen  ramifying  in  its  substance,  and  upon 
squeezing  the  blood  which  they  contain  from  the  larger  branches 
to  the  smaller,  it  will  be  found  to  pass  out  at  the  digested  ends  of 
the  vessels,  and  to  appear  like  drops  on  the  inner  surface. 

Though  I have  often  seen  such  appearances,  and  supposed  that 
they  must  have  been  seen  by  others,  yet  I was  quite  at  a loss  to 
account  for  them.  At  first  I supposed  them  to  have  been  produced 
during  life,  and  was  therefore  inclined  to  look  upon  them  as  the 
cause  of  death,  only  that  I never  found  they  had  any  connexion 
with  the  patient’s  symptoms ; but  1 was  still  more  at  a loss  to 
account  for  them  when  I discovered  they  were  most  frequent  in 
those  who  died  by  sudden  violence ; a circumstance  which  made 
me  suspect  that  the  true  cause  was  not  guessed  at.*  At  this  time 
I was  employed  in  making  experiments  upon  digestion  in  different 
animals,  all  of  which  were  killed  at  different  times,  after  having 
been  fed  with  various  kinds  of  food  : many  of  these  were  not 
opened  immediately  after  death,  and  in  some  of  them  I found  the 
above-described  appearances  in  the  stomach.  The  better  to  pursue 
my  inquiry  on  the  subject  of  digestion,  I procured  the  stomachs  of 
a vast  variety  of  fishes,  whose  deaths  are  always  violent,  and  who 
may  be  said  to  die  in  perfect  health,  with  their  stomachs  usually 

* The  first  time  that  I had  occasion  to  observe  this  appearance  where  death 
had  been  produced  by  violence,  and  where  it  could  not  therefore  easily  be  sup- 
posed to  be  the  effect  of  disease,  was  in  a man  who  had  his  skull  fractured  by 
one  blow  of  a poker.  Just  before  this  accident  he  had  been  in  perfect  health,  and 
had  taken  a hearty  supper  of  cold  meat,  cheese,  bread,  and  ale.  Upon  opening 
the  abdomen,  I found  that  the  stomach,  though  it  still  contained  a good  deal,  was 
dissolved  at  its  great  end,  and  a considerable  part  of  its  contents  lay  loose  in  the 
general  cavity  of  the  belly  ; a circumstance  which  puzzled  me  very  much.  The 
second  instance  was  in  a man  who  died  at  St.  George’s  Hospital,  a few  hours 
after  receiving  a blow  on  his  head  which  fractured  his  skull.  From  these  two 
cases,  among  various  conjectures  about  so  strange  an  appearance,  I began  to  sus- 
pect it  might  be  peculiar  to  cases  of  fractured  skull,  and  therefore,  whenever  I 
had  an  opportunity,  I examined  the  stomach  of  every  person  who  died  from  that 
accident ; but  I found  many  of  them  which  had  not  this  appearance.  I afterwards 
met  with  the  same  appearance  in  a man  who  had  been  hanged. 


148 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


full.  In  them  we  can  observe  the  progress  of  digestion  most  dis- 
tinctly, the  shape  of  their  stomachs  being  very  favourable  for  that 
purpose.  They  likewise  swallow  their  food  whole,  that  is,  without 
mastication,  and  swallow  fish  that  are  much  larger  than  the  digesting 
part  of  the  stomach  can  contain;  therefore  in  many  instances  the 
part  swallowed  which  was  lodged  in  the  digesting  part  of  the  sto- 
mach was  found  more  or  less  dissolved,  while  that  which  remained 
in  the  oesophagus  was  perfectly  sound  ; and  in  many  of  these  I saw 
the  digesting  part  of  the  stomach  itself  reduced  to  the  same  dis- 
solved state  as  the  digested  part  of  the  food. 

Being  employed  upon  this  subject,  and  therefore  enabled  to 
account  more  readily  for  appearances  which  had  any  connexion 
with  it,  and  observing  that  the  half-dissolved  parts  of  the  stomach 
were  similar  to  the  half-digested  food,  it  immediately  struck  me 
that  it  was  the  process  of  digestion  going  on  after  death  ; and  that 
the  stomach,  being  dead,  was  no  longer  capable  of  resisting  the 
powers  of  that  menstruum  which  itself  had  formed  for  the  digestion 
of  food.* 

These  appearances  of  the  stomach  after  death  throw  considerable 
light  on  the  principles  of  digestion,  and  show  that  it  neither  depends 
on  a mechanical  power,  nor  contractions  of  the  stomach,  nor' on 
heat,  but  something  secreted  in  the  coats  of  the  stomach,  and  throvv'n 
into  its  cavity,  which  there  animalizes  the  food,  or  assimilates  it  to 
the  nature  of  the  blood.f  The  power  of  the  gastric  juice  is  con- 
fined or  limited  to  certain  substances,  generally  of  the  vegetable 
and  animal  kingdoms;  and  although  this  menstruum  is  capable  of 
acting  independently  of  the  stomach,  yet  it  is  indebted  to  that  viscus 
for  its  existence  and  continuance. 

*■  ['riien  follows  in  the  original  paper: 

“ '\Yith  this  idea,  I set  about  making  experiments, to  produce  these  appearances 
at  pleasure,  which  would  have  taught  us  how  long  the  animal  ought  to  live  after 
feeding,  and  how  long  it  should  remain  after  death  before  it  is  opened  ; and  above 
all,  to  find  out  the  method  of  producing,  the  greatest  digestive  power  in  the  living 
stomach:  but  this  pursuitled  me  into  an  unbounded  field.” — Phil.  Trans.  (1772), 
p.  453.] 

I [In  the  original  paper  the  following  note  here  occurs:  “ In  all  the  animals, 
whether  carnivorous  or  not,  upon  which  I made  observations  or  experiments  to 
discover  whether  or  not  there  was  an  acid  in  the  stomach  (and  I tried  this  in  a 
great  variety),  I constantly  found  that  there  was  an  acid,  but  not  a strong  one,  in 
the  juices  contained  in  that  viscus  in  a natural  state.”  The  omission  of  this 
note  both  in  the  1st  and  2d  editions  of  the  Animal  (Economy  was  probably  a 
consequence  of  the  doubt  subsequently  entertained  by  Hunter  of  the  natural 
presence  of  an  acid  in  the  gastric  juice ; but  as  the  existence  of  hydrochloric  acid 
as  an  essential  constituent  of  the  animalizing  secretion  of  the  stomach  is  now 
satisfactorilj'  determined,  tve  have  thought  it  proper  to  restore  this  record  of  the 
agreement  of  a great  proportion  of  Hunter’s  experience  w'ith  that  of  late  observers 
on  this  subject.] 


SECRETION  IN  THE  CROP  OF  BREEDING  PIGEONS.  149 


12,  ON  A SECRETION  IN  THE  CROP  OF  BREEDING 
PIGEONS,  FOR  THE  NOURISHMENT  OF  THEIR 
YOUNG. 

The  nourishment  of  animals  admits,  perhaps,  of  as  much  variety 
in  the  mode  by  which  it  is  to  be  performed  as  any  circumstance 
connected  with  their  oeconomy,  whether  we  consider  their  numerous 
tribes,  the  different  stages  through  which  every  animal  passes,  or 
the  food  adapted  to  the  support  of  each  in  their  distinct  conditions 
and  situations.  We’are  likewise  to  include  in  this  view  that  endless 
variety  in  the  means  by  which  this  food  is  procured,  according  to 
the  class  of  the  animal  and  the  particular  stage  of  its  existence. 
If  the  food  was  the  same  through  every  period  of  the  life  of  an  animal ; 
if  every  individual  of  a tribe  lived  on  the  same  kind,  and  procured 
it  by  the  same  mode,  our  speculations  would  then  admit  of  a regular 
arrangement.  But  when  we  see  that  the  food  adapted  to  one  stage 
of  an  animal’s  life  is  rejected  at  another,  and  that  animals  of  one 
class  in  some  respects  resemble  those  of  another,  by  hardly  having 
any  food  peculiar  to  themselves,  the  subject  becomes  so  complicated 
that  it  is  not  surprising  if  we  are  at  a loss  to  arrange  the  various 
modes  by  which  animals  are  nourished. 

Animal  life  may  not  improperly  be  divided  into  three  states  or 
stages.  The  first  comprehends  the  production  of  the  animal  and 
its  growth  in  the  foetal  state ; the  second  commences  when  it 
emerges  from  that  state  by  what  is  called  the  birth,  yet  for  a certain 
time  must,  either  mediately  or  immediately,  depend  on  the  parent 
for  support;  the  third  may  be  said  to  take  place  when  the  animal 
is  fit  and  at  liberty  to  act  for  itself.  The  first  and  third  stages  are 
perhaps  common  to  all  animals;  but  there  are  some  classes,  as 
fishes,  spiders,  &c.,  which  seem  to  have  no  second  stage,  but 
pass  directly  from  the  first  to  what  is-  the  third  in  other  animals. 
Of  those  requiring  a second  stage,  the  polypus  and  the  viviparous 
animals  continue  to  derive  their  nourishment  immediately  from 
the  parent ; while  the  oviparous  are  for  some  time  supported  by 
a substan,ce  originally  formed  with  them,  and  reserved  for  that 
purpose.* 

There  is  infinite  variety  in  the  means  by  which  Nature  provides 

* [The  species  of  polypus  to  which  ISIr.  Hunter  here  refers  is  most  probably 
the  freshwater  gemmiparous  hydra;  but  the  period  during  which  the  young 
polype  is  growing  at  the  expense  of  the  parent  seems  rathei  to  correspond  to  the 
first  or  fcetal  stage  of  existence  than  the  second  ; when,  again,  the  communication 
with  the  digestive  sac  of  the  parent  is  obliterated,  tbe  young  polype  derives  its 
nourishment  from  without  by  the. exercise  of  its  tentacles,  until  it  is  finally  cast 
off.  The  viviparous  animals  are  the  Mammalia,  and  the  nourishment  alluded  to 
is  tlie  lacteal  secretion.  The  nutritious  substance  with  which  the  oviparous 
animals  continue  for  a short  period  to  be  supported  after  their  exclusion  from 
the  egg  is  the  yolk,  which  has  then  passed  into  the  abdomen,  where  it  is  finally 
absorbed.] 


14* 


150 


HUNTER  -ON  THE  ANIMAL  (ECONOMY. 


for  the  support  of  the  young  in  the  second  stage  of  animal  life. 
In  many  insects  it  is  effected  by  the  female  instinctively  depositing 
the  egg.  or  whatever  contains  the  rudiments  of  the  animal,  in  such 
a situation  that,  when  hatched,  it  may  be  within  reach  of  proper 
food  ; others,  astholhumble-bee  and  black-beetle  ‘ [^Blatta],'  collect  a 
quantity  of  peculiar  substance,  which  both  serves  as  a nidus  for 
the  egg,  and  nourishment  for  the  maggot,  when  the  embryo  arrives 
at  that  state.  Most  birds,  and  many  of  the  bee-tribe,  collect  food 
for  their  young ; when  at  a more  advanced  period  the  task  of  feed- 
ing them  is  performed  by  both  male  and  female,  with  an  exception 
in  the  common  bee,  the  young  ones  of  which  are  not  fed  by  either 
parent,  but  by  the  working-bees,  which  act  the  part  of  the  nurse. 
There  is  likewise  a number  of  animals  capable  of  supplying  im- 
mediately from  their  own  bodies  the  nourishment  proper  for  their 
offspring  during  this  second  stage,  a mode  of  nourishment  which 
has  hitherto  been  supposed  to  be  peculiar  to  that  class  of  animals 
which  Linnaeus  calls  Mammalia ; nor  has  it,  I imagine,  been  ever 
suspected  to  belong  to  any  other. 

1 have,  liowever,  in  my  inquiries  concerning  the  various  modes 
in  which  young  animals  are  nourished,  discovered  that  all  of  the 
dove  kind  are  endowed  with  a similar  power.  The  young  pigeon, 
like  the  young  quadruped,  till  it  is  capable  of  digesting  the  common 
food  of  its  kind,  is  fed  with  a substance  secreted  for  that  purpose 
by  the  parent  animal ; not,  as  in  the  Mammalia,  by  the  female 
alone,  but  also  by  the  male,  wdiich,  perhaps,  furnishes  this  nutriment 
in  a degree  still  more  abundant.  It  is  a common  property  of  birds, 
that  both  male  and  female  are  equally  employed  in  hatching,  and 
in  feeding  their  young  in  the  second  stage;  but  this  particular 
mode  of  nourishment,  by  means  of  a substance  secreted  in  their 
own  bodies,  is  peculiar  to  certain  kinds,  and  is  carried  on  in  the 
crop. 

Besides  the  dove  kind,  I have  some  reason  to  suppose  parrots 
to  be  endowed  with  the  same  faculty,  as  they  have  the  power  of 
throwing  up  the  contents  of  the  crop,  and  feeding  one  another.  I 
have  seen  the  cock  par’roquet  regularly  feed  the  hen,  by  first  filling 
his  own  crop,  and  then  supplying  her  from  his  beak.  Parrots, 
maccaws,  cockatoos,  &c.,  wlien  they  are  very  fond  of  the  person 
who  feeds  them,  may  likewise  be  observed  to  have  the  action  of 
throwing  up  the  food,  and  often  do  it.  The  cock  pigeon,  w'hen  he 
caresses  the  hen,  performs  the  same  kind  of  action  as  when  he 
feeds  his  young;  but  I do  not  known  if  at  this  time  he  throws  up 
anything  fro.m  the  crop. 

During  incubation  the  coats  of  the  crop  in  the  pigeon  are  gradually 
enlarged  and  thickened,  like  what  happens  to  the  udder  of  females 
of  the  class  Mammalia  in  the  term  of  uterine  gestation.  On  com- 
paring the  state  of  the  crop  when  the  bird  is  not  sitting,  with  its 
appearance  during  incubation,  the  difference  is  very  remarkable. 
In  the  first  case  it  is  thin  and  membranous ; but  by  the  time  the 
young  are  about  to  be  hatched,  the  whole,  except  what  lies  on  the 


ON  THE  GILLAROO-TKOUT. 


151 


trachea,  becomes  thicker,  and  takes  on  a glandular  appearance, 
having  its  internal  surface  very  irregular.  It  is  likewise  evidently 
more  vascular  than  in  its  former  stale,  that  it  may  convey  a quantity 
of  blood  sufficient  for  the  secretion  of  the  substance  which  is  to 
nourish  the  young  brood  for  some  days  after  they  are  hatched. 

Whatever  may  be  the  consistence  of  this  substance  when  just 
secreted,  it  most  probably  very  soon  coagulates  into  a granulated 
W'hite  curd,  for  in  such  form  I have  always  found  it  in  the  crop  ; 
and  if  an  old  pigeon  is  killed  just  as  the  young  ones  are  hatching, 
the  crop  will  be  foun4  as  above  described,  and  in  its  cavity  pieces 
of  white  curd,  mixed  with  some  of  the  common  food  of  the  pigeon, 
such  as  barley,  beans,  &c.  If  we  allow  either  of  the  parents  to 
feed  the  brood,  the  crop  of  the  young  pigeons  when  examined  will 
be  discovered  to  contain  the  same  kind  of  curdled  substance  as  that 
of  che  old  ones,  which  passes  from  thence  into  the  stomach,  where 
it  is  to  be  digested. 

The  young  pigeon  is  fed  for  a little  time  with  this  substance 
only,  as  about  the  third  day  some  of  the  common  food  is  found 
mingled  with  it:  as  the  pigeon  grows  older  the  proportion  of  com- 
mon food  is  increased  ; so  that  by  the  time  it  is  seven,  eight,  or 
nine  days  old,  the  secretion  of  the  curd  ceases  in  the  old  ones,  and 
of  course  no  more  will  be  found  in  the  crop  of  the  young.  It  is  a 
curious  fact  that  the  parent  pigeon  has  at  first  a power  to  throw 
up  this  curd  without  any  mixture  of  common  food,  although  after- 
wards both  are  thrown  up  according  to  the  proportion  required  for 
the  young  ones. 

I have  called  this  substance  curd,  not  as  being  literally  so,  but 
as  resembling  that  more  than  anything  I know  ; it  may,  however, 
have  a greater  resemblance  to  curd  than  we  are  perhaps  aware  of, 
for  neither  this  secretion,  nor  curd  from  which  the  wdiey  has  been 
pressed,  seems  to  contain  any  sugar,  and  do  not  run  into  the  acetous 
fermentation.  The  property  of  coagulating  is  confined  to  the  sub- 
stance itself,  as  it  produces  no  such  effect  when  mixed  with  milk. 

This  secretion  in  the  pigeon,  like  all  other  animal  substances, 
becomes  putrid  by  standing,  though  not  so  readily  as  either  blood 
6r  meat,  it  resisting  putrefaction  for  a considerable  time;  neither 
will  curd  much  pressed  become  putrid  so  soon  as  either  blood  or 
meat. 


13.  OBSERVATIONS  ON  THE  GILLAROO-TROUT,  COM- 
MONLY CALLED  IN  IRELAND  THE  GIZZARD- 
TROUT.* 

One  of  the  digestive  organs  of  the  gillaroo-trout  being  so  very 
remarkable  as  to  have  given  name  to  the  fish,  and  to  have  been 
considered  as  its  distinguishing  characteristic,  it  is  my  intention  to 

* [Originally  published  in  the  Philosophical  Transactions,  vol.  Ixiv.  (1774;)] 


152 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


inquire  whether  its  resemblance  to  a gizzard  be  sufficiently  strong 
to  render  the  term  of  gizzard-trout  a proper  appellation,  and  what 
place  its  stomach  ought  to  hold  among  the  corresponding  organs 
of  other  animals.  For  this  purpose  it  will  be  necessary  to  state 
certain  facts  connected  with  the  subject,  and  take  a general  view 
of  the  varieties  which  occur  in  the  digestive  organs  in  different 
animals. 

The  food  of  animals  may  be  divided  into  two  kinds,  what  does, 
and  what  does  not,  require  mastication  to  facilitate  digestion.  The 
flesh  of  animals  is  of  the  latter  kind  ; but  grain,  and  many  other 
substances  which  serve  for  aliment,  require  a previous  grinding  or 
trituration,  and  therefore  animals  living  on  this  kind  of  food  are 
furnished  with  organs  for  that  purpose.  Granivorous  quadrupeds 
have  the  two  powers,  for  mastication  and  digestion,  separate  or 
distinct  from  one  another;  the  first  being  executed  by  teeth,  which 
serve  as  so  many  grindstones  for  reducing  their  food  to  smaller 
parts,  before  it  is  conveyed  into  the  stomach  for  digestion;  but  the 
form  of  these  teeth  varies  very  considerably  in  different  animals, 
although  the  food  be  the  same.  This  grinding  also  fits  it  for  deglu- 
tition ; for  neither  grain  nor  herbs  could  be  swallowed  without 
having  first  been  masticated.  When  so  prepared,  it  is,  with  regard 
to  the  digestive  power,  rendered  similar  to  animal  food;  therefore 
in  many  of  the  granivorous  the  stomach  resembles  that  of  the 
carnivorous  animals  ; and  whenever  the  stomach  in  the  granivorous 
quadruped  departs  from  this  general  rule,  there  is  a peculiarity  in 
the  operations  of  digestion.  Birds  that  live  upon  substances,  for  the 
digestion  of  which  trituration  is  indispensably  necessary,  have  the 
powers  of  mastication  and  digestion  united  in  one  part,  the  gizzard, 
which  is  particularly  constructed  for  that  purpose,  but  is  more 
uniform  in  its  construction  than  the  teeth,  varying,  only  by  being 
stronger  or  weaker  in  its  powers;  therefore  the  genius  of  birds 
exhibits  less  variety,  respecting  the  organs  relating  to  digestion,  than 
the  quadruped.  In  granivorous  birds,  therefore,  one  single  organ 
answers  both  to  the  teeth  and  stomach  of  granivorous  quadrupeds, 
and  consequently  the  gizzard  alone  of  birds  will  as  clearly  point  out 
the  food  of  the  species  as  both  teeth  and  stomach  together,  in  those 
animals  in  whicli  the  two  offices  of  mastication  and  digestion  are 
not  performed  together  in  the  same  part. 

As  it  appears  to  be  the  difference  of  stomachs  only  that  fits  birds 
for  their  different  kinds  of  food,  as  there  is  little  difference  in  con- 
struction, excepting  only  in  strength  ; and  as  the  food  of  the  difterent 
species  is  of  every  kind,  from  the  hardest  grain  to  the  softest  animal 
matter,  we  may  conclude  that  every  gradation  of  the  stomach  is  to 
be  found  among  them,  from  the  true  gizzard,  which  is  one  extreme, 
to  the  mere  membranous  stomach,  which  is  the  other.  In  conse- 
quence of  this,  it  must  be  as  difficult  to  determine  the  exact  limits 
of  the  two  different  modes  of  construction  to  which  the  names  of 
gizzard  and  stomach  specifically  belong,  as,  in  any  other  case,  to 
distinguish  proximate  steps  in  the  slow  and  imperceptible  gradations 
of  Nature. 


ON  THE  GILLAROO-TROUT. 


153 


The  two  extremes  of  true  gizzard  and  membranous  stomach  are 
easily  defined  ; but  they  run  so  into  each  other,  that  the  end  of  one 
and  the  beginning  of  the  other  is  quite  imperceptible.  Similar  gra- 
dations are  observable  in  the  food  : the  kinds  suited  to  the  two  ex- 
tremes mixing  together  in  different  proportions  adapted  to  the  in- 
termediate states  of  stomach. 

A true  gizzard  is  composed  of  two  strong  muscles,  placed  opposite 
and  acting  upon  each  other,  like  two  broad  grindstones.  These 
muscles  are  joined  together  at  their  sides  by  a middle  tendon,  into 
which  the  muscular  fibres  are  inserted,  and  which  forms  the  nar- 
row anterior  and  posterior  sides  of  the  flat  quadrangular  cavity  in 
which  the  grinding  is  performed.  The  upper  end  of  this  cavity  is 
occupied  by  the  termination  of  the  oesophagus,  and  the  beginning  of 
the  intestine.  The  lower  end  consists  of  a thin  muscular  bag  con- 
necting the  edges  of  the  two  muscles  together. 

By  these  two  more  soft  and  flexible  substances  being  thus  inter- 
posed between  the  two  strong  grinding  muscles  a double  advantage 
is  gained;  for  whilst  one  gives  an  easy  passage  to  the  oesophagus 
and  gut,  when  both  act  together  they  serve  in  some  degree  as  a 
hinge,  on  which  the  two  muscles  may  be  said  to  move,  by  the  mid- 
dle tendon  allowing  of  a free  motion  of  the  grinding  surfaces  on  each 
other,  which  is  necessary  for  the  comminution  of  food. 

The  two  flat  lateral  sides  of  the  grinding  cavity  are  lined  with  a 
thick  horny  substance,  similar  to  a hard  and  thick  cuticle;  the  nar- 
row anterior  and  posterior  tendinous  parts  are  also  lined  with  a cu- 
ticle, but  not  so  strong  as  the  former;  this  horny  substance  is  gra- 
dually lost  at  one  end  in  a very  thin  cuticle,  which  lines  the  passages 
of  the  oesophagus  and  intestine  for  a little  way,  and  at  the  other  end 
is  lost  jn  the  same  manner  in  the  membranous  bag. 

The  two  large  muscles  may  be  considered  as  a pair  of  jaws,  whose 
teeth  are  occasionally  supplied,  being  small  rough  stones  or  pebbles 
W'hich  the  animal  swallows,  which  from  the  feeling  of  the  tongue 
can  distinguish  such  as  are  proper  from  those  which  are  not,  in- 
stantly dropping  out  of  its  mouth  such  as  are  smooth  and  otherwise 
unfit  for  the  purpose. 

Some  birds  with  gizzards  have  also  a craw  or  crop,  which  serves 
as  a reservoir,  and  for  softening  the  grain  ; but  as  all  of  them  have 
not  tlfis  organ  it  is  not  to  our  present  purpose. 

There  are  other  animals,  besides  this  class  of  birds,  w'hich  mas- 
ticate their  food  in  the  stomach  ; but  teeth  are  placed  there  by 
Nature;  of  this' kind -are  crabs  and  lobsters. 

The  gradation  from  gizzard  to  stomach  is  made  by  the  muscular 
sides  becoming  weaker  and  weaker,  and  the  food  keeps  pace  with 
this  change,  varying  gradually  from  vegetable  to  animal*  In  one 
point  of  view,  therefore,  food  may  be  considered  as  a first  principle, 
w’ith  respect  to  which  the  digestive  organs  with  their  appendages 

♦ [The  gizzards  of  birds  which  live  on  hard-coated  coleopterous  insects  are 
stronger  than  those  which  have  to  digest  soft  pulpy  fruits.] 


154 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


act  as  but  secondary  parts,  being  adapted  to  and  determined  by  the 
food  as  the  primary  object. 

We  find  then  that  in  all  granivorous  animals  there  is  an  appa- 
ratus for  the  mastication  of  the  food,  although  often  differing  in  con- 
struction and  situation  ; but  in  true  carnivorous  animals,  of  what- 
ever tribe,  mastication  not  being  so  necessary,  they  have  no  appa- 
ratus for  that  purpose.  The  teeth  of  such  quadrupeds  as  are  carni- 
vorous serve  chiefly  to  procure  food  and  prepare  it  for  deglutition ; 
the  same  thing  is  performed  in  the  true  carnivorous  birds  by  their 
beak  and  talons,  whose  office  it  is  to  procure  the  aliment  and  fit  it 
for  deglutition,  corresponding  in  this  respect  with  the  teeth  of  the 
others.  Applying  this  reasoning  to  fish,  it  seems,  at  first  sight,  as 
if  there  were  no  occasion  in  them  for  that  variety  of  structure  in  the 
digestive  organs  as  is  found  in  the  before-mentioned  quadrupeds  and 
birds,  the  food  of  fish  being  principally  of  one  sort,  namely  animal; 
which,  however,  with  regard  to  the  digestive  powers,  is  to  be  dis- 
tinguished into  two  kinds,  viz.,  common  soft  and  shell-fish.  Such 
fish  as  live  on  the  first  kind  have,  like  the  carnivorous  quadrupeds 
and  birds,  no  apparatus  for  mastication,  their  teeth  being  intended 
merely  for  catching  the  food  and  fitting  it  to  be  swallowed.  But 
the  shells  of  the  second  kind  of  food  render  some  degree  of  masti- 
cating power  necessary  to  fit  it  for  its  passage  either  into  the  sto- 
mach or  through  the  intestines ; and  accordingly  we  find  in  certain 
fish  a structure  suited  to  the  purpose. 

Thus  the  mouth  of  the  wolf-fish  is  almost  paved  with  teeth,  by 
means  of  which  it  can  break  shells  to  pieces  and  fit  them  for  the 
oesophagus  of  the  fish,  and  so  efiectually  disengage  the  food  from 
them,  that  though  it  lives  upon  such  hard  food,  the  stomach  does  not 
differ  from  that  of  other  fish ; the  organs  of  mastication  and  digestion, 
therefore,  in  this  animal,  exactly  correspond  to  those  of  many  gra- 
nivorous quadrupeds. 

Other  fish,  on  the  contrary,  approach  nearer'  to  the  structure  of 
birds  by  having  their  stomach  furnished  to  a certain  degree  with  a 
masticating  power,  which  in  many  is  very  imperfect  compared  with 
the  gizzards  of  fowls.  Perhaps  the  difference  is  only  what  the  dif- 
ference of  food  will  properly  allow  ; as  in  fish  which  have  this  power, 
the  food  being  still  animal,  and  in  general  but  imperfectly  covered 
with  the  shell,  it  probably  requires  only  to  be  broken,  perhaps  hardly 
that,  for  the  mere  purposes  of  digestion,  as  food  is  digested  when 
introduced  into  the  stomach  in  silver  balls  with  only  a fgw  small 
holes,  but  it  may  be  necessary  to  fit  the  shells  for  passing  along  the 
intestines  after  the  fish  is  digested.  In  the  BuUa  lignaria  of  Linnaeus 
this  apparatus  is  more  perfect,  consisting  of  two  bones,  ■w'hich  we 
must  suppose  capable  of  grinding  hard  shells;  but  the  food  of  gra- 
nivorous birds  requires  to  be  ground  into  a kind  of  meal. 

Of  all  the  fish  I have  seen,  the  mullet  is  the  most  complete  instance 
of  this  structure,  its  strong  muscular  stomach  being  evidently 
adapted,  like  the  gizzard  of  birds,  to  the  two  offices  of  mastication 
and  digestion.  The  stomach  of  the  fish  now  before  us  holds  the 
second  place. 


ON  ANIMALS  PRODUCING  HEAT. 


155 


But  still  neither  of  these  stomachs  can  be  justly  ranked  as  gizzards, 
since  they  want  some  of  the  most  essential  characters,  viz.,  a power 
and  motion  fitted  for  grinding,  and  the  horny  cuticle.*  The  stomach 
of  the  gillaroo-trout  is,  however,  more  globular  than  that  of  most 
fish,  better  adapted  for  small  food,  and  endued  with  sufficient  strength 
to  break  the  shells  of  small  shell-fish;  which  will  probably  be  best 
done  by  having  more  than  one  in  the  stomach  at  a time,  and  also  by 
taking  pretty  large  and  smooth  stones  into  the  stomach,  which  will 
answer  the  purpose  of  breaking,  but  not  so  well  that  of  grinding,  nor 
will  they  hurt  the  stomach,  as  they  are  smooth,  when  swallowed ; 
but  this  stomach  can  scarcely  possess  any  power  of  grinding,  as 
the  whole  cavity  is  lined  with  a fine  villous  coat,  the  Internal  surface- 
of  which  appears  ev’erywhere  to  be  digestive,  and  by  no  means 
fitted  for  mastication. 

The  stomach  of  the  common  stream-trout  is  exactly  of  the  same 
structure  with  that  of  the  gillai'oo  ; but  its  coat  not  so  thick  by  two 
thirds.f  How  far  this  dilference  in  thickness  of  stomach  is  suffi- 
cient to  form  a distinct  species,  or  barely  a variety  of  the  same,  is 
only  to  be  determined  by  experiment.! 

The  oesophagus  in  the  trout  is  considerably  longer  and  smaller 
than  in  many  other  classes  of  fish. 

The  intesines  are  similar  to  those  of  the  salmon,  herring,  sprat,  &c. 

The  pancreas  is  appendiculated. 

The  teeth  show  them  to  be  fish  of  prey. 

So  far  as  we  are  led  to  determine  by  analogy,  we  must  not  con- 
sider the  stomach  of  this  fish  as  a gizzard,  but  as  a true  stomach. 


14.  EXPERIMENTS  AND  OBSERVATIONS  ON  ANIMALS, 
WITH  RESPECT  TO  THE  POWER  OF  PRODUCING 
HEAT.§ 

Some  late  ingenious  experiments  and  observations,  published  in 
the  Philosophical  Transactions,!!  upon  a power  which  animals  seem 

* [We  have  examined  the  gizzard  of  the  mullet  {Mugil  Capita,  Cuv.),  and  find 
that  it  is  lined  by  a distinct  layer  of  rough  and  easily  separable  cuticle.] 

f The  common  stream-trout  swallows  shell-fish,  and  also  pretty  large  smooth 
stones,  which  serve  as  a kind  of  shell-breakers. 

X Viz.,  take  some  gillaroo-trout,  male  and  female,  and  put  them  jnto  water  in 
which  there  are  no  trout,  to  see  if  they  continue  the  same.» 

§ [This  Essay  includes  the  greater  part  of  two  papers,  one  published  with  the 
title  ‘Experiments  on  Animals  and  Vegetables,  with  respect  to  the  Power  of  pro- 
ducing Heat,’  in  the  Philosophical  Transactions,  vol.  Ixv.  (read  June  22,  1775)  ; 
the  other,  ‘On  the  Heat,  &c.,  of  Animals  and  Vegetables,’  in  the  Philosophical 
Transactions,  vol.  Ixviii.  (read  June  19,  and  Nov.  13,  1777.)] 

II  [‘  Experiments  and  Observations  in  a heated  Room,’  by  Charles  Blagden, 
M.D.,  F.R.S.,  vol.  Ixv.,  p.  111.] 


[They  are  considered  to  be  varieties  of  the  Salma  Faria,  Linn.,  by  the  best 
modern  naturalists;  see  Yarrell’s  ‘ British  Fishe.s,’  vol.  ii.,  p.  57.] 


15G 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


to  possess  of  generating  cold,  induced  me  to  look  over  my  notes, 
containing  some  whicli  I had  made  in  the  year  1766,  indicating  an 
opposite  power  in  animals,  whereby  they  are  capable  of  resisting 
any  external  cold  while  alive,  by  generating  within  themselves  a 
degree  of  heat  sufficient  to  counteract  it.  Those  experiments  were 
not  originally  instituted  with  any  expectation  of  the  event  which  re- 
sulted from  them,  but  for  the  purpose  of  satisfying  myself  whether 
an.  animal  could  retain  life  after  being  frozen,  as  has  been  confidently 
asserted  both  of  fishes  and  snakes.  For  that  these,  after  being  frozen, 
still  retain  so  much  of  life  as  when  thawed  to  resume  their  vital 
actions,  is  a fact  so  well  attested  that  we  are  bound  to  believe  it ; 
and  had  my  experiment  succeeded,  it  was  my  intention  to  have  tried 
the  effects  of  freezing  on  living  animals  to  a much  greater  degree 
than  can  ever  happen  accidentally. 

I mention  these  circumstances  to  account  for  what  might  other- 
wise be  attributed  to  negligence  and  inattention,  namely,  the  little 
nicety  that  was  observed  in  measuring  the  precise  degree  of  cold 
applied  in  the  experiments.  Accuracy  in  this  particular  was  not 
aimed  at,  being  of  no  conseirjuence  in  tlie  inquiry,  more  immediately 
before  me.  The  cold  was  first  produced  by  means  of  ice  and  snow 
with  sal  ammoniac  or  sea-salt,  to  about  the  10°  of  Fahrenheit’s  ther- 
mometer : ice  was  then  mixed  with  spirit  of  nitre.;  but  what  degree 
of  cold  was  thus  produced  I did  not  examine.  This  cold  mixture 
was  made  in  a tub  surrounded  with  woollen  cloths,  and  covered 
with  the  same,  to  prevent  the  effects  of  the  heat  of  the  atmosphere 
upon  the  mixture  itself,  and  to  preserve,  as  much  as  possible,  a cold 
atmosphere  within  the  vessel.  Animal  juices,  as  the  blood,  freeze 
at  25°,  so  that  a piece  of  dead  flesh  could  be  frozen  in’an  atmosphere 
cooled  to  that  point.' 

EXPERIMENTS. 

Experiment  I.  was  made  on  two  carp.  These  were  put  into  a 
glass  vessel  with  common  river  water,  which  was  placed  in  the 
freezing  mixture.  The  water  not  freezing  fast  enough,  to  hasten 
that  effect  as  much  cooled  snow  was  added  as  to  render  the  whole 
thick.  The  snow  round  the  carp  melting,  we  put  in  more  fresh  snow, 
which,  melting  also,  was  repeated  several  times,  till  we  grew  tired, 
and  at  last  left  them  covered  up  in  the  yard  to  freeze  by  the  joint 
operation  of  the  surrounding  mixture  and  the  natural  cold  of  the  at- 
mosphere."* They  were  frozen  at  last,  after  having  exhausted  the 
whole  powers  of  life  in  the  production  of  heat.  That  this  was  really 
the  cqse,  could  not  be  known  till  I had  completed  that  part  of  the 
experiment  for  which  the  whole  was  begun,  viz.,  the  thawing  of  the 

* [This  experiment  is  alluded  to  by  Dr.  Blagden,  who  observes,  “The  power 
of  generating  heat  seems  to  attend  life  very  universally.  Not  to  mention  other 
well-known  experiments,  Mr.  Hunter  found  a carp  preserve  a coat  of  fluid  water 
round  him  long  after  all  the  rest  of  the  water  in  the  vessel  had  been  congealed  by 
a very  strong  freezing  mixture.”— PAi7.  Trans.,  Ixv,,  p.  122.] 


ON  ANIMALS  PRODUCING  HEAT, 


157 


animals.  It  was  done  very  gradually ; but  the  animals  did  not, 
with  flexibility,  recover  life  ; and  while  in  this  cold,  showed  signs  of 
great  uneasiness  by  their  violent  motions.  JV.B.  In.  some  of  these 
experiments,  where  air  was  made  the  conductor  of  the  cold  and 
heat,  that  the  heat  might  be  more  readily  carried  off  from  the  animal, 
a leaden  vessel  was  used.  It  w'as  small  for  the  same  reason  ; and  as 
it  was  necessary  for  the  animal’s  respiration  that  the  mouth  of  the 
vessel  should  communicate  with  the  open  air,  it  was  made  deep,  that 
the  cold  of  the  atmosphere  round  the  animal  might  not  be  diminished 
too  quickly  by  the  w'armth  of  the  open  air,  which  would  have  spoiled 
it  as  a conductor. 

Experiment  II.  was  upon  a dormouse,  the  vessel  in  which  it  vs'as 
confined  being  sunk  in  the  cold  mixture  almost  to. its  edge.  The 
atmosphere  round  the  animal  soon  cot)led  ; its  breath  froze  as  it 
came  from  the  mouth  ; a hoar-frost  gathered  on  its  whiskers,  and  on 
all  the  inside  of  the  vessel,  and  the  external  points  of  the  hair  be- 
came covered  with  the  same.  While  this  w'as  coins:  on  the  animal 
showed  signs  of  great  uneasiness  ; sometimes  it  would  coil  itself  into 
a round  form,  to  preserve  its  extremities  and  confine  its  heat;  and 
finding  that  ineffectual,  would  then  endeavour  to  make  its  escape.* 
Its  motions  became  less  violent  by  the  sinking  of  the  vital  powers  : 
its  feet  were  at  last  frozen  : but  we'  wmre  not  able  to  keep  up  the 
cold  a sufficient  time  to  freeze  the  whole  animal,  the  hair  being  so 
bad  a conductor  of  fieat  that  the  consumption  w'as  not  more  than 
the  animal  pow'ers  were  capable  of  supporting.^ 

Experiment  III.  wms  made  with  another  dormouse;  and  taught 
by  the  failure  of  the  last  experiment,  I took  care  that  the  hair 
should  not  a second  time  be  an  obstruction  to  our  success.  Having, 
therefore,  first  made  the  animal  wmt  all  over,  that  its  heat  might 
be  more  rapidly  carried  off,  it  was  put  into  a leaden  vessel,  and  the 
whole  placed  in  the  cold  mixture  as  before.  The  animal  soon  gave 
signs  of  feeling  the  cold,  by  repeated  attempts  to  make  its  escape; 
and  the  breath  and  water  evaporating  from  its  body  being  soon  frozen, 
appeared  like  a hoar-frost  on  the  sides  of  the  vessel  and  on  its  whis- 
kers ; but  while  the  vigour  of  life  lasted  it  defied  the  approach  of  the 
cold.  However,  from  the  hair  being  w'et,  and  thereby  rendered  a 
good  conductor,  there  was  a much  greater  consumption  of  heat  than 
in  the  former  experiment,  which  hastened  on  the  diminution  of  the 
power  of  producing  it.  The  animal  dying,  soon  became  stiff,  and, 
upon  being  thawed,  was  found  quite  dead. 

Experiment  IV.  A toad  being  put  into  a vessel  with  wmter,  at 
such  a depth  as  not  to  cover  its  mouth,  was  placed  in  the  mixture 

* This  shows  that  cold  carried  to  a great  degree  rather  rouses  than  depresses 
the  animal  action  : but  it  appears,  from  many  circumstances'  and  observations, 
that  a certain  degree  of  cold  produces  inactivity  both  in  living  and  sensative 
principle,  wliich  will  be  further  illustrated  hereafter. 

f These  experiments  were  made  in  presence  of  Dr.  George  Fordyce  and  Dr. 
Erwin,  teacher  of  Chemistry  at  Glasgow,  the  latter  of  whom  came  in  accidentally 
in  the  middle  of  our  operations. 


15 


158 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


cooled  to  between  10°  and  15°.  The  w'ater  froze  so  near  to  the 
body  of  the  animal  as  quite  to  inclose  it,  but  without  destroying 
life ; yet,  though  not  frozen,  it  hardly  ever  recovered  the  use  of 
its  limbs. 

Experiment  V.  was  with  a snail,  which  froze  very  soon,  in  a cold 
between  10°  and  13°.  These  two  last  experiments  were  made  in 
the  winter,  when  the  living  powers  of  the  animals  selected  for  the 
trial  are  very  weak ; they  might  have  resisted  the  cold  more  strong- 
ly in  the  summer.  Why  the  animals  mentioned  in  the  above  ex- 
periments died  before  they  were  frozen,  while  those  which  are 
exposed  to  the  atmosphere  in  very  cold  climates  do  not,  is  a point  I 
shall  not  pretend  to  determine,  not  knowing  the  difference  between 
theeflects  of  a natural  and  an  artificial  cold.  It  may  be  accounted 
for  by  supposing  that  the  natural  cold  in  climates  in  which  animals 
are  found  frozen  is  so  intense  as  to  produce  congelation  immediately, 
before  the  powers  of  life  are  exhausted ; at  least  whether  it  is  so  or 
not  is  w'orthy  of  inquiry. 

It  appears  from  the  above  experiments,  first.  That  most  proba- 
bly the  animals  were  deprived  of  life  before  they  were  frozen; 
secondly.  That  there  was  an  exertion  or  expense  of  animal  power  in 
resisting  the  effects  of  cold,  proportioned  to  the  necessity ; thirdly. 
That  this  exertion  was  in  proportion  to  the  perfection  of  the  animal 
and  the  natural  heat  proper  to  each  species  and  to  each  age.  This 
exertion  might  also  perhaps  depend  in  some  degree  on  other  cir- 
cumstances not  hitherto  observed  ; for  from  Experiments  II.  and  III. 
upon  dormice,  I find  that  in  the  animals  which  are  of  a constitution  to 
retain  nearly  the  same  heat  in  all  temperatures  of  the  air,  it  required 
the  greatest  cold  I could  produce  to  overcome  this  resisting  power; 
while  by  Experiments  IV.  and  V.  on  the  toad  and  snail,  whose 
natural  heat  is  not  always  the  same,  but  is  altered  very  materially 
according  to  the  external  heat  or  cold,  this  power  was  exhausted  in 
a degree  of  cold  not  exceeding  10°  or  15°;  and  the  snail  being  the 
most  imperfect  of  the  two,  its  powers  of  generating  heat  appeared 
to  be  much  the  weakest. 

That  the  imperfect  animals  will  allow  of  a considerable  variation 
in  the  temperature  of  heat  and  cold,  is  proved  by  the  following  ex- 
periments. The  thermometer  being  at  45°,  the  ball  was  intro- 
duced by  the  mouth  into  the  stomach  of  a frog,  which  had  been 
exposed  to  the  same  cold.  It  rose  to  49°.  I then  placed  the  frog 
in  an  atmosphere  made  warm  by  heated  water,  where  I allowed  it 
to  stay  twenty  minutes ; and  upon  introducing  the  thermometer 
into  the  stomach,  it  raised  the  quicksilver  to  64°.  To  what  degree 
the  more  imperfect  animals  are  capable  of  being  rendered  hotter 
and  colder  at  one  time  than  another,  I have  not  yet  ascertained  ;* 

* [The  snail  {Cychstomum  thermale)  which  lives  in  the  hot  springs  of  Abano 
feeds,  moves  about  with  great  activity,  and  propagates  in  water  of  the  temperature 
of  100°  Fahrenheit.  The  Entozoa  of  warm-blooded  animals  become  in  acertaia 
degree  torpid  in  cold  water,  but  revive  and  exhibit  lively  motions  when  placed 
in  warm  water  of  95.°  Fahrenheit.] 


ON  ANIMALS  PRODUCING  HEAT. 


159 


but  the  torpidity  of  these  animals  in  our  winter  is  probably  owing 
to  the  great  change  wrought  in  their  temperature  by  the  external 
heat  and  cold.  The  cold  in  their  bodies  is  to  such  a degree  as  in 
a great  measure  to  put  a stop,  while  it  lasts,  to  the  vital  functions ; 
while  in  warmer  climates  no  such  eftect  is  produced.* 

This  variety  (in  the  power  of  producing  heat)  not  only  takes 
place  in  animals  of  different  orders,  but  in  some  degree  in  the  same 
animal  at  different  ages,  even  according  to  the  different  age  of  the 
parts  in  the  same  animal:  a young  animal  requires  more  warmth 
than  one  full-grown  ; and  although  an  animal  is  equally  old  in  all  its 
original  parts,  yet,  there  are  often  new  ones  formed  in  consequence 
of  disease ; and  we  find  that  these  new  or  young  parts  in  animals 
are  not  so  able  to  support  life  as  the  old,  at  least  for  some  time  : but 
as  animals  are  of  different  ages,  and  the  same  animal  is  always 
growing  older,  and  of  coui’se  more  and  more  perfect,  they  then  be- 
come more  capable  of  generating  heat  than  when  they  were 
younger.f  This,  however,  has  its  limitations,  for  after  a certain 
period  they  again  lose  this  power,  and  therefore  require  a less 
strongly  conducting  medium,  or  w'arm  atmosphere. 

This  power  of  generating  heat  seems  to  be  a property  in  an 
animal  while  alive.  In  the  more  perfect  animals  it  is  to  preserve  a 
standard  heat;  and  as  they  are  most  commonly  in  an  atmosphere 
colder  than  themselves,  they  have  most  commonly  occasion  to 
exert  it,  and  it  is  therefore  a power  only  of  opposition  and  resist- 
ance; for  it  is  not  found  to  exert  itself  spontaneously  and  unpro- 
voked, but  must  always  be  excited  by  the  energy  of  some  external 
frigorific  agent,  or  disease ; yet  it  is  natural  to  such  animals  that 
this  power  should  be  called  forth,  as  will  be  observed  by  and  by. 
It  does  not  depend  on  the  motion  of  the  blood,  as  some  have  sup- 
posed, because  it  likewise  belongs  to  animals  which  have  no  circu- 
lation and  the  nose  of  a dog,  which  is  always  nearly  of  the  same 

* [The  Reptiles  and  many  of  the  Invertebrate  animals  of  tropical  climates  seek 
their  hiding-places  and  fall  into  a state  of  lethargy  during  the  dry  season,  when 
the  heat  is  most  intense.  A quadruped  of  Madagascar,  the  tenrec,  which  is 
nearly  allied  to  our  hedgehog,  becomes  lethargic  atihe  dry  season,  when  its  in- 
sect food  is  inaccessible.] 

f [Young  animals  consume,  in  proportion,  less  oxygen  than  adults;  conse- 
quently, a less  proportion  of  carbonic  acid  is  formed  in  the  change  of  the  arterial 
into  the  venous  blood,  and  a less  amount  of  heat  is  extricated.  When  exposed 
to  cold  they  become  torpid,  lose  their  heat,  and  also  their  sensibility,  in  which 
latter  cirhumstance,  and  in  some  other  points,  they  differ  considerably  from  the 
hybernaling  animal  in  its  state  of  lethargy.] 

f:  [An  argument  of  this  importance  deserved  to  be  stated  with  more  circum- 
stance. Mr.  Hunter  does  not  say  what  the  animals  are  which  have  no  circu- 
latiorr.  It  is  possible,  however,  that  he  was  alluding  to  bees.  But  these  insects 
we  know  enjoy  a circulation,  governed,  as  his  own  dissections  show,  by  a dorsal 
heart.  And  insects  manifest  the  power  of  generating  heat  above  that  of  other 
invertebrate  animals  precisely  in  consequence  of  the  greater  activity  of  their  loco- 
motive, respiratory,  and  sanguiferous  functions.  It  is  true,  however,  that  mere 
motion  of  the  blood  is  not  a cause  of  animal  heat,  because  the  circulation  goes  on 
in  the  hybernaling  animal  when  in  its  cold  and  lethargic  state  ; but  the  blood’s 
motion  is  here  inoperative  as  a cause  of  heat^  because  in  torpidity  no  chemical 


160 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


heat  in  all  temperatures  of  the  air, is  well  supplied  with  blood;*  al- 
though we  must  allow,  where  this  power  is  greatest  the  circulation 
is  the  quickest.  Neither  can  it  be  said  to  depend  upon  the  nervous 
system,  for  it  is  found  in  animals  that  have  no  brain  or  nerves. 
However,  it  must  be  allowed  that  all  that  class  which  possess  this 
power  in  the  highest  degree  have  the  largest  brain,  although  this 
power  is  not  in  the  least  in  proportion  to  the  quantity  of  brain  in  that 
class.f  It  is  most  probable  that  it  arises  from  some  other  prin- 
ciple; a principle  so  connected  with  life  that  it  can,  and  does,  act 
independently  of  circulation,  sensation,  and  volition,  and  is  that 
power  which  preserves  and  regulates  the  internal  machine.  This 
power  of  generating  heat  is  in  the  highest  perfection  when  the 
body  is  in  health;  and  in  many  deviations  from  that  state  we  find 
that  its  action  is  extremely  uncertain  and  irregular,  sometimes 
rising  higher  than  the  standard,  and  at  other  times  falling  much 
below  it.  Instances  of  this  we  have  in  different  diseases,  and  even 
in  the  same  disease,  within  very  short  intervals  of  time.  A very 
remarkable  one  fell  under  my  own  observation,  in  a gentleman 
who  was  seized  with  an  apoplectic  fit;  and  while  he  lay  insensible 
in  bed,  covered  with  blankets,  I found  that  his  whole  body  would, 
in  an  instant,  become  extremely  cold  in  every  part,  continuing  so 
for  some  time  ; and,  as  suddenly,  would  become  extremely  hot. 
While  this  was  going  on  alternately  there  was  no  sensible  altera- 
tion in  his  pulse  fur  several  hours.J 

Being  satisfied  of  the  foregoing  fact,  that  animals  had  a power 
of  generating  heat,  I pursued  the  subject  still  further ; not  so  much 
with  a view  to  account  for  animal  heat,  as  to  observe  the  different 
phenomena,  with  the  variations  or  difference  in  the  heat  in  different 

change  takes  place  in  the  blood  during  its  passage  through  the  capillaries,  either 
of  the  systemic  or  pulmonic  systems  of  vessels;  it  is  only  venous  blood  that  is 
moving.] 

* [The  temperature  of  the  nose  of  a dog  is  lowered  by  the  constant  evaporation 
of  the  moisture  excreted  from  its  surface;  when  this  secretion  is  checked  in  con- 
sequence of  internal  disease,  then  the  nose  soon  grows  hot;  and  the  dryness  and 
heat  of  this  part,  both  in  the  dog  and  other  animals,  form  a common  symptom  of 
loss  of  health,  as  we  have  frequently  had  occasion  to  observe  in  the  animals  in 
the  Zoological  Gardens.] 

t[Although,  from  the  experiments  on  vegetables  subsequently  given,  it  appears 
that  vital  heat  is  not  dcjiendent  on  a nervous  system  ; yet  it  has  been  shown  that 
the  production  of  heat  in  warm-blooded  animals  is  modified  by  the  nervous  in- 
fluence. See  the  Physiological  Researches,  ‘ On  the  Influence  of  the  Brain  on 
the  action  of  the  Heart,  and  on  the  generation  of  Animal  Heat,’  by  0.  C.  Brodie, 
F.R.S.,  Phil.  Trans.,  vol.  ci.,  p.  36;  vol.  cii.,  p.  380;  also  the  experiments  of 
Home  and  Mayo,  Phil.  Trans.,  vol.  cxv.,  p.  7;  and  by  Lega]]ois,  Jnnn/es  de 
Chimie,  t.  iv.  1817.] 

f:  [Here  ends  the  first  paper  in  the  65th  vol.  of  the  Phil.  Trans.  The  second 
communication  commences  as  follows  : “ In  the  course  of  a variety  of  experiments 
on  animals  and  vegetables,  I have  frequently  observed  that  the  result  of  experi- 
ments in  the  one  has  explained  the  oeconomy  of  the  other,  and  pointed  out  some 
principle  common  to  both  ; I have  therefore  collected  some  experiments  which 
relate  to  the  heat  and  cold  of  those  substances;”  and  then  proceeds  as  in  the 
text.] 


ON  ANIMALS  PRODUCING  HEAT. 


161 


animals.  In  the  course  of  my  experiments,  having  found  varia- 
tions in  the  degree  of  heat  and  cold  in  the  same  experiment,  for 
which  I could  not  account,  I suspected  that  this  might  arise  from 
some  imperfection  in  the  construction. of  the  thermometer.  I men- 
tioned to  Mr.  Ramsden  my  objections  to  the  common  construction 
of  that  instrument,  and  my  ideas  of  one  more  perfect  in  its  nature, 
and  better  adapted  to  the  experiments  in  which  I was  engaged. 
He  accordingly  made  me  some  very  small  thermometers,  six  or 
seven  inches  long,  not  above  two-twelfths  of  an  inch  thick  in  the 
stem,  having  the  external  diameter  of  the  ball  very  little  larger 
than  that  of  the  stem,  on  which  was  marked  the  freezing  point. 
The  stem  was  embraced  by  a small  ivory  scale,  so  as  to  slide  upon 
it  easily,  and  retain  any  position.  Upon  the  hollow  surface  of  this 
scale  were  marked  the  degrees,  which  were  seen  through  the  stem. 
By  these  means  the  size  of  the  thermometer  was  very  much  reduced, 
and  it  could  be  applied  to  soft  bodies  with  much  more  ease  and 
certainty,  and  in  many  cases  in  which  the  former  ones  could  not 
be  conveniently  used;  I therefore  repeated  with  it  such  of  my 
former  experiments  as  had  not  at  first  proved  satisfactory,  and 
found  the  degrees  of  heat  very  different,  not  only  from  what  I had 
expected,  but  also  from  what  I had  found  by  my  former  experi- 
ments with  thermometers  of  the  common  construction. 

I have  observed  above,  and  find  it  supported  by  every  experi- 
ment 1 have  made  on  the  heat  and  cold  of  animals,  that  the  more 
perfect  have  the  greater  power  of  retaining  a certain  degree  of  heat, 
which  may  be  called  their  standard  heat,  and  allow  of  much  less 
variation  than  the  more  imperfect  animals  ; however,  it  will  appear 
from  the  three  experiments  which  I am  now  going  to  relate,  that 
many,  if  not  all  of  the  more  perfect,  are  still  incapable  of  keeping 
constantly  to  one  degree,  but  may  be  altered  from  their  standard 
heat  either  by  external  applications  or  disease.  These  variations 
are  much  greater  below  that  standard  than  above  it,  the  perfect 
animals  having  a greater  power  of  resisting  heat  than  cold,  so  that 
they  are  commonly  near  their  ultimate  heat.  Indeed  we  do  not 
want  any  other  proof  of  a variation  than  our  own  feelings,  being 
all  sensible  of  heat  and  of  cold,  which  sensations  could  not  be  pro- 
duced without  an  alteration  really  taking  place  in  the  parts  affected; 
and  that  alteration  could  not  take  place  if  they  did  not  become 
actually  warmer  or  colder.  I have  often  cooled  my  hands  to  such 
a degree  that  I could  warm  them  by  immersing  them  in  water  just 
pumped ; therefore  my  hands  were  really  colder  than  the  pump- 
water. 

An  increase  of  absolute  heat  must  alter  the  texture  or  position  of 
the  parts,  so  as  to  produce  the  sensation  which  we  call  heat : and 
as  that  heat  is  diminished,  the  texture  or  position  of  the  parts  is 
altered  in  a contrary  way,  and,  when  carried  to  a certain  degree, 
becomes  the  cause  of  the  sensation  of  cold.  Now  these  effects  could 
not  take  place  in  either  case  without  an  increase  or  decrease  of  ab- 
solute heat  in  the  part ; heat,  therefore,  in  some  one  of  its  different 

15* 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


ie3 

degrees,  must  be  present.  I sliall  not  in  this  place  attempt  to  settle 
whether  heat  is  a body  or  matter,  or  only  a property  of  matter, 
which  appears  to  me  to  be  merely  a difference  in  terms',  fora 
property  must  belong  to  something.  When  heat  is  applied  to  the 
surface  of  the  body  the  skin  becomes  in  some  degree  heated  accord- 
ing to  the  application,  which  may  be  carried  so  far  as  actually  to  • 
burn  the  living  parts  ; on  the  contrary,  in  a cold  atmosphere  a man’s 
hand  may  become  so  cold  as  to  lose  that  sensation  altogether,  and 
change  it  for  pain.  Absolute  heat  and  cold  may  be  carried  so  far 
as  even  to  alter  the  structure  of  the  parts  upon  which  the  actions 
of  life  depend. 

As  animals  being  subject  to  variations  in  the  degrees  of  heat  and 
cold  from  external  applications  are  of  course,  in  this  respect,  aflected 
in  some  measure  like  inanimate  matter;  and  therefore,  as  parts  are 
elongated  or  recede  from  the  common  mass,  these  efiects  more 
readily  take  place  ; for  instance,  all  projecting  parts  and  extremities, 
more  especially  toes,  fingers,  noses,  ears,  combs  of  fowls,  particu- 
larly of  the  cock,  are  more  readily  cooled,  and  are  therefore  most 
subject  to  be  affected  by  cold.  Animals  are  not  only  subject  to  an 
increase  and  decrease  of  heat,  similar  to  inanimate  matter,  but  the 
transition  from  one  to  the  other  (as  far  as  they  admit  of  it)  is  nearly 
as  quick.  I shall  not,  however,  confine  myself  to  sensation  alone, 
as  that  is  in  some  degree  regulated  by  habit;  for  a habit  of  uni- 
formity in  the  application  of  heat  and  cold  to  an  animal  body  renders 
it  more  sensible  of  the  smallest  variation  in  either;  while  by  the 
habit  of  variety  it  will  become,  in  a proportional  degree,  less  sus- 
ceptible of  all  such  sensations.  This  is  proved  every  day,  in  cold 
weather,  by  people  who  are,  accustomed  to  clothe  themselves  warm. 
In  them  the  least  exposure  to  cold  air,  although  the  eflect  produced 
in  the  skin  is  perhaps  not  the  hundredth  part  of  a degree,  imme- 
diately gives  the  sensation  of  cold,  even  through  the  thickest  cover- 
ing; those,  on  the  contrary,  who  have  tieen  used  to  go  thinly 
clothed,  can  bear  the  variation  of  some  degrees  without  being  sen- 
sible of  it ; of  this  the  hands  and  feet  afford  an  instance  in  point,  ex- 
citing the  sensation  of  cold  when  applied  to  another  part  of  the 
body,  without  having  before  given  to  the  mind  an  impression  of 
cold  existing  in  these  parts  themselves.  The  projecting  parts  and 
the  extremities  are  those  w'hich  admit  of  the  greatest  change  in 
their  degrees  of  heat  and  cold  w'ithout  materially  affecting  the 
animal  or  even  its  sensations.  I find  that  by  heat  or  cold  externally 
applied  to  such  parts,  the  thermometer  may  be  made  to  rise  or  fall ; 
but  not  in  an  equal  proportion  as  when  applied  to  inanimate  matter. 
IXor  are  the  living  parts  cooled  or  heated  in  the  same  proportion, 
as  appears  from  tlie  application  of  the  thermometerto  the  skin  ; for 
the  cuticle  is  to  be  considered  as  a dead  covering,  capable  of  re- 
ceiving greater  degrees  of  heat  and  cold  than  the  living  parts  un- 
derneath ; and  as  it  might  be  suspected  that  the  whole  of  the  varia- 
tion was  in  this  covering,  to  remove  any  such  doubt  I made  the 
following  experiments. 


ON  ANIMALS  PRODUCING  HEAT. 


163 


Experiment  I.  I placed  the  ball  of  the  thermometer  under  my 
tongue  where  it  was  perfectly  covered  by  all  the  surrounding  parts; 
and  having  kept  it  there  for  some  minutes,  I found  that  it  rose  to 
97°:  yet  it  rose  no  higher  by  being  continued  there.  I then  took 
several  pieces  of  ice,  about  the  size  of  walnuts,  and  put  them  in  the 
same  situation,  allowing  them  only  to  melt  in  part,  that  the  appli- 
cation of  cold  might  be  better  kept  up,  occasionally  spitting  out  the 
water  arising  from  the  solution.  Having  continued  this  for  ten 
minutes,  I found,  on  introducing  my  thermometer,  that  it  fell  to  77°; 
so  that  the  mouth  at  this  part  had  lost  20°  of  heat.  The  ther- 
mometer gradually  rose  to  97°  again;  but  did  not  in  this  experi- 
ment sink  so  low  as  it  would  have  done  in  the  hand,  if  a piece  of  ice 
had  been  held  in  it  for  the  same  length  of  time.  Perhaps  the  surface 
under  the  tongue  being  surrounded  with  warm  parts  renders  it  next 
to  an  impossibility  to  cool  it  below  that  degree;  but  1 rather  sus- 
pect that  such  parts  as  the  hand  will  allow  of  greater  latitude  in 
this  respect,  from  having  .insensibly  acquired  the  habit  of  varying 
the  degree  of  cold,  and  becoming  of  course  less  susceptible  of  its  im- 
pressions, and  therefore  less  easily  excited. 

As  a further  proof  that  the  more  perfect  animals  are  capable  of 
varying  their  heat  in  some  measure  according  to  the  external  heat 
applied,  I shall  adduce  the  following  experiments  made  on  the  human 
subject. 

The  mouth  being  a part  so  frequently  in  contact  with  the  external 
atmosphere  in  the  action  of  breathing,  whatever  is  put  into  it  may 
be  supposed  to  be  influenced  by  that. atmosphere ; this  will  always 
render  an  experiment  made  in  that  part,  relative  to  heat  and  cold, 
somewhat  uncertain.  I imagined  that  the  urethra  would  answer 
better,  because,  being  an  internal  cavity,  it  can  only  be  influenced 
by  heat  and  cold  applied  to  the  external  skin  of  the  parts.  I 
imagined  also  that,  whatever  effects  the  application  of  heat  and 
cold  might  have,  they  would  sooner  take  place  in  the  urethra,  as 
being  a projecting  part,  than  in  any  otlier  part  of  the  body;  and 
therefore,  if  living  animal  substance  was  in  any  degree  subject  to 
the  common  laws  of  matter  in  this  respect,  the  urethra  would  be 
readily  affected.  To  determine  this  1 procured  a person  who 
allowed  me  to  make  such  experiments  as  1 thought  necessar}\ 

Experiment  II..  I introduced  the  ball  of  my  thermometer  into 
the  urethra  about  an  inch  ; which  having  remained  there  about  a 
minute,  the  quicksilver  rose  to  92°;  at  two  inches  it  rose  to-  93°;  at 
four  inches  to  94°;  and  when  the  ball  had  got  as  far  as  the  bulb 
of  the  urethra,  where  it  was  surrounded  by  warm  parts,  the  quick- 
silver rose  to  97°. 

Experiment  III.  These  parts  being  immersed  for  one  minute  in 
water,  heated  only  to  65°,  and  the  thermometer  introduced  about  an 
inch  and  a half  into  the  urethra,  the  quicksilver  rose  to  69°;  which 
w'as  repeated  several  times  with  the  same  result.  To  discover  if 
there  were  any  difference  in  the  quickness  of  the  transition  of  heat 
and  cold  in  living  and  dead  parts,  and  to  determine  if  the  extent  to 


]64 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


wliich  each  would  go  were  likewise  different,  I procured  a dead 
penis,  for  the  purpose  of  making  the  comparative  experiments  that 
follow  ; being  clearly  of  opinion  that  all  such  trials  should  be  as 
similar  as  possible,  except  in  those  points  where  the  difference  (if 
there  is  any)  makes  the  essential  part  of  the  experiment. 

Experiment  IV.  The  heat  of  the  penis  of  a living  person,  an 
inch  and  a half  within  the  urethra,  being  found  exactly  92°;  and 
the  dead  one  being  heated  to  the  same  degree,  I had  both  immersed 
in  the  same  vessel,  with  the  water  at  50°,  when,  by  introducing 
the  thermometers  several  different  times,  I was  able  to  note  the 
comparative  quickness  with  wdiich  they  cooled  from  92°,  and  ob- 
served that  the  dead  cooled  sooner  by  two  or  three  minutes  ; the 
living  sunk  the  quicksilver  to  58°,  and  the  dead  to  50°:  the  ther- 
mometer, although  continued  there  some  time  longer,  fell  no  lower. 
I repeated  this  experiment  several  times,  with  the  same  result; 
although  at  one  time  there  was  a small  difference  in  the  degrees  of 
heat  of  the  penis  and  also  of  the  water;  but  the  diflerence  in  the 
result  was  nearly  proportional  in  all  the  three  different  trials,  there- 
fore the  same  conclusions  may  be  drawn  from  them.  In  these  last 
experiments  very  little  difference  was  observed  between  the  cool- 
ing of  a dead  and  of  a livitjg  part;  a circumstance  which  we 
cannot  suppose  to  take  place  uniformly  through  the  whole  body, 
as  in  that  case  living  animals  would  always  be  of  the  same  degree 
of  heat  with  the  atmosphere  in  which  they  live.  The  subject  of 
these  experiments  not  choosing  to  have  the  part  cooled  lower  than 
53°  or  54°,  prevented  my  observing  if  the  powers  of  generating 
heat  were  exerted  to  a greater  degree  when  the  heat  was  brought 
so  low  as  to  threaten  destruction  ; but  by  some  experiments  on 
mice,  which  will  be  related  hereafter,  it  will  appear  that  the  ani- 
mal powers  are  roused  to  exert  themselves  in  this  respect  when 
necessary. 

Having  found,  from  the  above  experiments,  that  parts  of  an 
animal  were  capable  of  being  cooled  below  the  common  or  natural 
heat,  I proceeded  to  make  others,  with  a view  to  ascertain  if  the 
same  parts  were  capable  of  being  made  much  hotter  than  the 
standard  heat  of  animals.  The  experiments  were  made  in  the 
same  manner  as  the  former,  only  the  water  was  now  hotter  than 
the  natural  heat  of  the  animal. 

Experiment  V.  The  natural  heat  of  the  parts  being  92°,  they 
were  immersed  for  two  minutes  in  water  heated  to  113°,  and,  the 
thermometer  being  introduced  as  before,  the  quicksilver  rose  to 
100°  and  a half.  This  experiment  I also  repeated  several  times, 
but  could  not  raise  the  heat  of  the  penis  beyond  1002°  : this  was 
probably  owing  to  the  person  not  being  able  at  the  time  to  bear 
the  application  of  water  warmer  than  113°.  By  was  of  compari- 
son, I made 

Experiment  VI.  The  living  and  dead  parts  being  both  immersed 
in  water,  gradually  made  warmer  and  warmer  from  100°  to  118°, 
and  continued  in  that  heat  for  some  minutes,  the  dead  part  raised 


ON  ANIMALS  PRODUCING  HEAT. 


165 


the  thermometer  to  114°,  while  the  living  raised  it  no  higher  than 
1024°.  It  was  observed,  by  the  person  on  whom  the  experiment 
was  made,  that  after  tho  parts  had  been  in  the  water  about  a 
nainute,  the  water  did  not  feet  hot,  but  on  its  being  agitated  it  felt 
so  hot  that  he  could  hardl}'-  bear  it.  Upon  applying  the  thermometer 
to  the  sides  of  the  living  glans,  the  quicksilver  immediately  fell 
from  118°  to  about  104°,  while  it  did  not  fall  more  than  a degree 
when  put  close  to  the  dead  ; so  that  the  living  glans  cooled  the  sur- 
rounding water  to  a certain  distance.* 

Experiment  VII.  The  heat  of  the  rectum  in  the  same  man  was 
98°  and  a half  exactly. 

In  the  second,  third,  fourth,  fifth,  and  sixth  experiments,  an  in- 
ternal cavity,  which  is  both  very  vascular  and  sensible,  was 
evidently  influenced  by  external  heat  and  cold,  though  only  applied 
to  the  skin  of' the  part ; while  in  the  seventh  experiment  another 
part  of  the  same  body,  where  external  heat  and  cold  could  make 
little  or  no  impression,  was  of  the  standard  heat.  Although  it  will 
appear,  from  experiment,  that  the  rectum  is  not  the  warmest  part 
of  an  animal,  yet,  in  order  to  determine  how  far  the  heat  could  be 
increased  by  stimulating  the  constitution  to  a degree  sufficient  to 
quicken  the  pulse,  I repeated  the  seventh  experiment  after  the  man 
had  eaten  a hearty  supper  and  drank  a bottle  of  wine,  which  in- 
creased the  pulse  from  73°  to  87°,  and  yet  the  thermometer  only^ 
rose  to  98°  and  a half. 

Having  formerly  made  experiments  upon  dormice  during  the 
sleeping  season,  with  a view  to  see  if  there  w'ere  any  alteration  in 
the  animal  oeconomy  at  that  time,  I found  among  my  notes  an  ac- 
count of  some  which  appear  to  our  present  purpose  ; but  to  be  more 
certain  of  the  accuracy  of  the  former  experiments,  I repeated  them 
■^ith  my  new  thermometer. 

Experiment  Vlll.  In  a room,  in  which  the  temperature  of  the  air 
was  between  50°  and  60°,  a small  opening  was  made  in  the  belly  of 
a dormouse,  of  a sufficient  size  to  admit  the  ball  of  my  thermometer, 
which,  being  introduced  into  the  belly  at  about  the  middle  .of  that 
cavity,  rose  to  80°,  and  no  higher. 

Experiment  IX.  The  mouse  was  put  into  a cold  atmosphere  of 
15°  above  0,  and  left  there  for  fifteen  minutes;  after  which,  the 
thermometer  being  introduced  a second  time,  it  rose  to  85°. 

Experiment  X.  The  mouse  w'as  again  put  into  a cold  atmosphere 
for  fifteen  minutes;  and  the  thermometer  being  introduced,  the 
quicksilver  a't  first  rose  to  72°  only,  but  gradually  came  up  to  83°, 
84°,  and  85°. 

Experiment  XI.  It  was  put  a third  time  into  the  cold  atmosphere, 
and  allowed  to  stay  there  for  thirty  minutes:  the  lower  part  of  the 

* This  might  furnish  an  useful  hint  respecting  bathing  in  water,  whether  colder 
or  warmer  than  the  heat  of  the  body  : for  if  intended  to  be  either  colder  or  hotter, 
it  will  soon’be  of  the  same  temperature  with  that  of  the  body ; therefore  in  a large 
bath  the  patient  should  move  from  place  to  place,  and  in  a small  one  there  should 
be  a constant  succession  of  water  of  the  intended  heat. 


166 


HUNTER  ON  THE  ANIMAL  OECONOMY. 


mouse,  at  the  bottom  of  (he  dish,  was  almost  frozen ; the  whole  of 
the  animal  was  numbed,  and  a good  deal  weakened.  The  ther- 
mometer being  introduced,  the  heat  was  found  to  vary  in  different 
parts  of  the  belly:  in  the  pelvis,  near  the  parts  most  exposed  to 
the  cold,  it  was  as  low  as  62°;  in  the  middle,  among  the  intestines, 
about  70°;  but  near  the  diaphragm  it  rose  to  80°,  82°,  84°,  and 
85°;  so  that  in  the  middle  of  the  body  the  heat  had  decreased  10°. 
Finding  a variation  in  different  parts  of  the  -same  cavity  in  the 
same  animal,  I repeated  the  same  experiments  upon  another 
dormouse. 

Experiment  XII.  Having  brought  a healthy  dormouse,  which  had 
been  asleep  from  the  coldness  of  the  atmosphere,  into  a room  in 
which  there  was  a fire  (the  atmosphere  at  64°),  I introduced  the 
thermometer  into  its  belly,  nearly  at  the  middle,  between  the  thorax 
and  pubis,  and  the  quicksilver  rose  to  74°-or  75°;  turning  the  ball 
towards  the  diaphragm,  it  rose  to  80°;  and  when  I applied  it  to  the 
liver,  it  rose  to  815°. 

Experiment  XIII.  The  mouse  being  placed  in  an  atmosphere  at 
20°,  and  left  there  half  an  hour,  when  taken  out  was  very  lively, 
even  much  more  so  than  when  put  in.  Introducing  the  thermometer 
into  the  lower  part  of  the  belly,  the  quicksilver  rose  to  91°;  and 
upon  turning  it  up  to  the  liver  to  93°. 

Experiment  XIV.  The  animal  being  replaced  in  the  cold  atmo- 
sphere at  30°  for  an  hour,  the  thermometer  was  again  introduced 
into  the  belly;  at  the  liver  it  rose  to  93°;  in  the  pelvis  to  92°;  the 
mouse  continuing  very  lively. 

Experiment  XV.  It  was  again  put  back  into  an  atmosphere, 
cooled  to  19°,  and  left  there  an  hour;  the  thermometer  at  the 
diaphragm  was  87°;  in  the  pelvis  83°;  but  the  animal  was  now  less 
lively.  , 

Experiment  XVI.  Having  been  put  into  its  cage,  the  thermo- 
meter being  placed  at  the  diaphragm,  in  two  hours  afterwards  was 
at  93°. 

As  I ‘was  unable  to  procure  hedgehogs  in  the  torpid  state,  to 
ascertain  their  heat  during  that  period,  I got  my  friend  Mr.  Jenner,* 
surgeon,  at  Berkeley,  to  make  the  same  experiments  on  that  animal, 
that  I might  compare  them  with  those  in  the  dormouse;  and  his 
account  is  as  follows: 

“ Experiment  I.  In  the  winter,  the  atmosphere  at  44°,  the  heat 
of  a torpid  hedgehog,  in  the  pelvis,  was  45°,  and  at  the  diaphragm 
48^°. 

“ Experiment  II.  The  atmosphere  26°,  the  heat  of  a torpid 
hedgehog,  in  the  cavity  of  the  abdomen,  was  reduced  so  low  as  30°. 

“ Experiment  III.  The  same  hedgehog  was  exposed  to  the  cold 
atmosphere  of  26°  for  two  days,  and  the  heat  of  the  rectum  was 
found  to  .be  93°;  the  wound  in  the  abdomen  being  now  so  small 
that  it  would  not  admit  the  thermometer. 


[Afterwards  Dr.  Jenner,  the  discoverer  of  Vaccination.] 


ON  ANIMALS  PRODUCING  HEAT. 


1G7 


“ A comparative  experiment  was  made  with  a puppy,  the  at- 
mosphere at  50°;  the  heat  in  the  pelvis,  as  also  at  the  diaphragm, 
was  102°. 

“ In  summer,  the  atmosphere  at  78°,  the  heat  of  the  hedgehog, 
in  an  active  state,  in  the  cavity  of  the  abdomen,  towards  the  pelvis, 
was  95°;  at  the  diaphragm  U?®.” 

We  find  from  these  experiments,  that  the  heat  of  the  animal  is 
increased  under  the  circumstances  of  cold,  whenever  there  are 
actions  to  be  carried  on  for  which  heat  is  necessary. 

In  the  experiments  on  the  first  dormouse  the  heat  of  the  animal 
was  80°,  which  is  below  the  standard  heat  of  the  actions  of  that 
animal ; and  after  being  put  into  the  cold  mixture  its  heat  W'as 
raised  to  85°.  In  the  second  dormouse  the  heat  was  raised,  by 
repeated  experiments,  from  75°  to  93°.  This  question  naturally 
occurs  here : Was  the  increase  of  heat  in  the  animals  generated  to 
resist  the  artificial  cold  produced  by  placing  them  in  a cold  atmo- 
sphere? or  was  it  owing  to  a wound  having  been  made  into  the 
cavity  of  the  abdomen,  and  an  exertion  of  the  animal  pow-ers  being 
required  to  repair  the  injury,  which  exertion  could  not  take  place 
without  the  increased  degree  of  heat  ? That  it  was  in  consequence 
of  the  wound,  appears  evident  from  the  experiment  made  upon  the 
second  hedgehog;  for  in  an  atmosphere  of  26°  of  heat  it  was  in  a 
very  torpid  state,  and  did  not  raise  the  thermometer  higher  than 
30°;  but  after  being  wounded  and  put  back  into  the  cold,  and  kept 
there  for  two  days,  its  heat  in  the  rectum  was  93°,  and  so  far  from 
being  torpid,  it  was  lively,  and  the  bed  in  which  it  lay  felt  warm."* 

Why  the  heat  of  the  dormouse  should  be  so  low  as  80°,  in  an 
atmosphere  of  between  50°  and  60°,  is  not  easily  accounted  for, 
except  as  the  effect  of  sleep.  But  I should  very  much  suspect  that 
sleep,  simply  considered,  is  out  of  the  question,  it  being  an  effect 
that  takes  place  in  all  degrees  of  heat  and  cold.  In  animals  whose 
voluntary  actions  are  suspended  by  cold,  that  appears  to  produce 
its  effect  by  acting  in  a certain  degree  as  a sedative,  in  consequence 
of  which  the  animal  faculties  arc  proporlionably  weakened,  though 
they  still  retain,  even  under  such  circumstances,  the  power  of 
carrying  on  all  the  functions  of  life.  Beyond  this  point  cold  seems 
to  act  as  a stimulant,  and  rouses  the  animal  powers  to  action  for 
self-preservation.  It  is  more  than  probable  that  most  animals  are 
in  this  predicament,  and  that  there  is  a degree  of  cold  corresponding 
with  every  particular  order  of  animals,  by  which,  when  applied, 
the  voluntary  actions  must  be  suspended. 

When  a man  is  asleep  he  is  colder  than  when  awake;  and  I find 
in  general  that  the  difference  is  about  one  degree  and  a half;  some- 
times less.  But  this  difference  in  the  degree  of  cold  between  sleep- 
ing and  waking  is  not  a cause  of  sleep,  but  an  effect ; for  many 
diseases  produce  a much  greater  degree  of  cold  in  the  animal 

* It  is  found,  from  experiments,  that  the  heat  of  an  inflamed  part  is  nearly  the 
greatest  or  standard  heat  of  the  animal,  it  appearing  to  be  a part  of  the  process 
of  inflammation  to  raise  the  heat  up  to  the  standard. 


1G3 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


without  giving  the  least  tendency  to  sleep  ; therefore  the  inactivity 
of  animals  from  cold  must  be  different  from  sleep.  Besides  all  the 
operations  of  perfect  life,  as  digestion,  sensation,  &c.,  are  going  on 
in  the  time  of  natural  sleep,  at  least  in  the  perfect  animals;  but 
none  of  these  operations  are  performed  in  the  torpid  state  of 
animals.* 

To  see  if  the  result  of  these  experiments  upon  dormice  was  pe* 
culiar  to  that  species,’  I wished  to  repeat  the  same  experiments  upon 
common  mice,  for  which  purpose,  in 

Experiment  XVII.  I made  use  of  one  strong  and  vigorous;  and 
the  atmosphere  being  at  60°,  I introduped  the  thermometer  into  the 
abdomen  ; the  ball  being  at  the  diaphragm  the  quicksilver  was 
raised  to  90°,  but  at  the  pelvis  only  to  96|°. 

Here  there  was  a real  difference  of  about  9°  between  the  dor- 
mouse and  the  common,  the  dormouse  only  raising  it  to  80°,  in  two 
animals  of  the  same  size,  in  some  degree  of  the  same  genus,  and  at 
the  same  season  of  the  year,  and  the  atmosphere  of  nearly  the  same 
temperature. 

Experiment  XVIII.  The  same  mouse  was  put  into  a cold  atmo- 
sphere of  13°  for  an  hour,  and  then  the  thermometer  was  introduced 
as  before;  but  the  animal  had  lost  heat,  for  the  quicksilver  at  the 
diaphragm  was  raised  only  to  83°,  in  the  pelvis ’to  78°. 

Here  the  real  heat  of  the  animal  was  diminished  16°  at  the  dia- 
phragm, and  18°  in  the  pelvis,  while  in  the  dormouse  it  gained  5°, 
but  lost  upon  a repetition. 

Experiment  XIX.  In  order  to  determine  whether  an  animal  that 
is  weakened  has  the  same  powers,  with  respect  to  preserving  heat 
and  cold,  as  one  that  is  vigorous  and  strong,  I weakened  a mouse 

> 

* [Some  recent  experiments  of  Dr.  Marshall  Hall  confirm  the  accuracy  of  the 
distinction  here  drawn  between  sleep  and  torpidity,  and  also  show  that  the 
ordinary  sleep  of  hybernatincr  warm-blooded  animals  diti’ers  from  that  of  non- 
hybernaiing  species,  by  inducing  a more  impaired  state  of  the  respiration,  and  a 
diminution  of  the  power  of  evolving  of  heat.  Although  a consciousness  or  sen- 
sibility be  lost,  automatic  susceptibility  of  impressions  is  remarkably  perfect 
during  torpi<lity.  Dr.  Hall  states  that  the  slightest  touch  applied  to  one  of  the 
spines  of  the  torpid  hedgehog  immediately  rouses  it  to  draw  a deep  sonorous 
inspiration,  which  is  its  characteristic  response  to  such  disturbance  while  in  that 
state.  The  merest  shake  induces  few  respirations  in  the  hybernating  bat.  (Phil. 
Trans.,  1832,  p.  15.)  So  also  with  respect  to  circulation,  this  vital  operation 
appears  to  be  performed  nnii.terruptedly,  though  slowly,  during  hybernation. 
M.  Prunelle  (JInnales  du.  Museum,  tom.  xviii.,  p.  28),  found  that  the  pulsations 
of  the  heart  of  a hat,  which,  while  it  is  awake  and  active  amount  to  200  in  a 
minute,  are  reduced  to  50  or  55  when  it  is  torpid.  Dr.  M.  Hall,  who  succeeded, 
by  an  ingenious  contrivance,  in  subjecting  the  wing  of  a torpid  bat  to  microscopi- 
cal examination,  found  the  circulation  to  be  slow  in  the  minute  arteries  and  veins ; 
but  the  beat  of  the  heart  was  regular,  and  generally  about  twenty-eight  times  in 
a minute.  {Ibid.  p.  17.)  The  blood  which  is  thus  circulated  is  venous,  the  respi- 
ration being  nearly,  if  not  totally,  suspended;  and  its  propulsion  in  this  state  is  ' 
explained  on  the  augmented  irritability  of  the  muscular  system,  which  is  mani- 
fested by  the  double  heart  of  the  torpid  mammal  being  stimulated  to  contract  by 
carbonized  blood,  like  the  heart  of  the  cold-blooded  and  slow-breathing  batrachian 
reptile.] 


ON  ANIMALS  PRODUCING  HEAT. 


169 


by  fasting,  and  then  introduced  the  ball  of  the  thermometer  into  its 
belly  ; the  ball  being  at  the  diaphragm,  the  quicksilver  rose  to  97°; 
in  the  pelvis  to  95°,  being  two  degrees  colder  than  the  strong  mouse. 
The  tnouse  being  put  into  an  atmosphere  as  cold  as  the  other,  and 
the  thermometer  again  introduced,  the  quicksilver  stood  at  79°  at 
the  diaphragm,  and  74°  in  the  pelvis. 

In  this  experiment  the  heat  at  the  diaphragm  was  diminished 
18°,  in  the  pelvis  21°. 

This  greater  diminution  of  heat  in  the  second  than  in  the  first  we 
may  suppose  proportional  to  the  decreased  power  of  the  animal, 
arising  from  w'ant  of  food. 

To  determine  how  far  different  parts  of  other  animals  than  those 
already  mentioned  were  of  different  degrees  of  heat,  I made  the 
following  experiments  upon  a healthy  dog. 

Experiment  XX.  The  ball  of  the  thermometer  being  introduced 
two  inches  within  the  rectum,  the  quicksilver  rose  to  1005°.  The 
chest  of  the  dog  was  then  opened,  and  a wound  made  into  the  right 
ventricle  of  the  heart;  and  immediately  on  the  ball  being  introduced, 
the  quicksilver  rose  to  101°  exactly.  A wound  was  next  made 
some  way  into  the  substance  of  the  liver,  and  the  ball  being  intro- 
duced, the  quicksilver  rose  to  1001°.  It  was  next  introduced  into 
the  cavity  of  the  stomach,  where  it  stood  exactly  at  101°.  All 
these  experiments  were  made  within  a few  minutes. 

Experiment  XXL  The  thermometer  was  introduced  into  the 
rectum  of  an  ox,  and  the  quicksilver  rose  exactly  to  994°. 

Experiment  XXII.  This  was  also  repeated  upon  a rabbit,  and 
the  quicksilver  rose  to  994°. 

From  experiments  on  mice  and  upon  the  dog,  it  plainly  appears 
that  every  part  of  an  animal  is  not  of  the  same  degree  of  heat ; 
and  hence  we  may  reasonably  infer,  that  the  heat  of  the  vital 
parts  of  man  is  greater  than  either  the  mouth,  rectum,  or  the 
urethra. 

To  determine  how  far  my  idea  w'as  just,  that  the  heat  of  animals 
varied  in  proportion  to  their  degree  of  perfection,  I made  the  fol- 
lowing experiments  upon  fowls,  which  I considered  as  one  remove 
below  w'hat  are  commonly  called  quadrupeds. 

Experiment  XXIII.  I introduced  the  ball  of  the  thermometer 
successively  into  the  intestinum  rectum  of  several  hens,  and  found 
that  the  quicksilver  rose  as  high  as  103°,  1034°,  and  in  one  of  them 
to  104°. 

Experiment  XXIV.  I made  the  same  experiments  on  several 
cocks,  and  the  result  was  the  same. 

Experiment  XXV.  To  determine  if  the  heat  of  the  hen  was  in- 
creased when  she  was  prepared  for  incubation,  I repeated  the 
twenty-third  experiment  upon  several  sitting  or  clucking  hens;  in 
one  the  quicksilver  rose  to  104°,  in  another  to  1034°,  in  a third  to 
103°,  as  in  the  twenty-third  experiment. 

Experiment  XXVI.  I placed  the  ball  of- the  thermometer  under 
‘ . 16 


170 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


the  same  hen,  in  whose  rectum  the  quicksilver  was  raised  to  104°, 
and  found  the  heat  as  great  as  in  tlie  rectum. 

Experiment  XXVII.  Having  taken  some  of  the  eggs  from  under 
the  same  hen,  where  the  chick  W'as  about  three  parts  formed,  I 
broke  a hole  in  the  shell,  and,  introducing  the  ball  of  the  ther- 
mometer, found  that  the  quicksilver  rose  to  99^°.  In  some  that 
were  addled  I found  the  heat  not  so  high  by  two  degrees ; so  that 
the  life  in  the  living  egg  assisted  in  some  degree  to  support  its  own 
heat. 

Is  the  increase  of  three  or  four  degrees  of  heat,  which  is  the  dif- 
ference found  between  the  fowl  and  the  quadruped,  for  the  purpose 
of  incubation?  The  heat  in  the  eggs,  which  W'as  caused  and  sup- 
ported by  that  of  the  fowls,  was  not  above  the  standard  of  the 
quadrupeds  ; and  it  would  probably  have  been  less  if  the  heat  of  the 
hen  had  not  been  so  great. 

Finding,  from  the  above  experiments,  that  fowls  w'ere  some 
degrees  w-armer  than  that  class  comcnonly  called  quadrupeds 
(although  certainly  less  perfect  animals),  I chose  to  continue  the 
experiments  upon  the  same  principle,  and  made  the  following  upon 
those  of  a still  inferior  order.  The  next  remove  from  the  fowl 
being  what  is  commonly  called  the  Amphibia. 

Experiment  XXVIII.  I introduced  the  thermometer  into  the 
stomach,  and  afterwards  into  the  anus  of  a healthy  viper,  and  the 
quicksilver  rose  from  58°  (the  heat  of  the  atmosphere  in  which  it 
was)  to  G8° ; so  that  it  was  ten  degrees  warmer  than  the  common 
atmosphere.'^ 

Experiment  XXIX.  Having  ascertained  the  heat  of  the  water  in 
a pond,  in  which  there  were  carp,  to  be  655°,  I took  a carp  out  of 
this  water,  and  having  introduced  the  thermometer  into  its  stomach, 
the  quicksilver  rose  to  69°;  so  that  the  difference  between  the  water 
and  the  fish  was  only  S5°.-j' 

♦ Experiment  XXX.  The  heat  of  the  atmosphere  at  56  ; some 
earthw’orms  were  put  into  a glass  vessel,  and  a thermometer  being 
immersed  among  them,  the  quicksilver  stood  at  585°. 

This  experiment  w'as  repeated  ; the  atmosphere  at  55°:  and  the 
worms  were  found  to  be  57°. 

Experiment  XXXI.  The  atmosphere  at  54°;  four  black  slugs 

* [The  observations  of  Czermack  correspond  with  the  above  experiment.  He 
fo'und  that  the  difference  between  the  temperature  of  the  animal  and  that  of  the 
surrounding'  medium  vvas  greater  in  serpents  and  lizards,  than  in  other  reptiles. 
The  temperature  of  a X.xix\.\e  {Chehmia  Mydas)  ,was  82°^  when  the  surrounding 
atmosphere  was  84°.  That  of  a frog  was  48°  when  the  surrounding  water  was 
44°.  That  of  a Proteus  was  64°,  the  surrounding  water  being  56°i]  , ,, 

f [Certain  saltwater  fishes,  as  the,  bonito  and  thunny,  which  have  fhe  gil]s, 
supplied,_with  nerves  of  unusual  magnitude,  apd  therefore  probably  enjoy  a more- 
energetic  respiration,,  which  have  also  a very,  powerful  heart,  and  the  quantity  of 
red  blood  such  as  to  give  the  muscles  a dark  red,  colour,  manifest  a higher  degfee 
of  temperature  than  the  white  fishes  of  fresh  water^  on  which  Mr.  Hunter  experir 
mented.  Dr.  John  Davy  found  that  the  bonito  kac)  a temperature  of  99°  , Fahren- 
heit when  the  surrounding  medium  was;  80°. 5.  See  Philos.  Trans.,  18351] 


ON  ANIMALS  PRODUCING  HEAT. 


171 


were  put  into  a small  vessel,  and  a thermometer  immersed  among 
them  stood  at  55i°. 

Experiment  XXXII.  The  atmosphere  at  56°;  three  leeches  were 
put  into  a.  small  glass  vessel,  and  a thermometer  immersed  among 
them  stood  at  57°. 

This  experiment  was  repeated  ; the  atmosphere  at  54° ; when  the 
thermometer  stood  at  55^°. 

To  see  how  far  the  colder  animals  had  a power  of  preserving 
their  standard  heat  when  exposed  to  severe  cold,  I made  the  fol- 
lowing experiments. 

Experiment  XXXIII.  A viper,  whose  heat  was  68°,  was  put  into 
a pan,  and  the  pan  into  a cold  mixture  of  about  10°;  after  remain- 
ing there  about  ten  minutes  had  its  heat  reduced  to  -37°.  Being 
allowed  to  stay  ten  minutes  longer,  the  mixture  at  13°,  its  heat 
was  reduced  to  35.°  It  was  continued  ten  minutes  more  in  the 
mixture  at  20,  and  its  heat  was  reduced  to  31°;  nor  did  it  sink 
lower,  its  tail  beginning  to  freeze,  and  the  animal  now  becoming 
very  weak.  It  may  be  remarked,  that  it  cooled  much  slower 
than  many  of  the  animals  mentioned  in  the  following  experiments. 

The  frog  being  in  its  structure  more  similar  to  the  viper  than 
to  either  the  fowl  or  fish,  I made  the  following  experiments  on  that 
animal. 

Experiment  XXXIV".  I introduced  the  ball  of  the  .thermometer 
into  its  stomach,  and  the  quicksilver  stood  at  44°.  1 then  put  the 

frog  into  a cold  mixture,  and  the  quicksilver  sunk  to  31°;  the 
animal  appeared  almost  dead,  but  recovered  very  soon : beyond 
this  point  it  was  not  possible  to  lessen  the  heat  without  destroying 
the  animal.  But  its  decrease  of  heat  was  quicker  than  in  the  viper, 
although  the  mixture  Was  nearly  the  same. 

The  next  experiments  were  made  on  fishes. 

Experiment  XXX  VT  In  an  eel,  the  heat  in  the  stomach,  which  at 
first  was  at  37°,  sunk,  after  it  had  been  some  time  in  the  cold 
mixture,  to  31°.  The  animal  at  that  time  appeared  dead,  but  was 
found  to  be  alive  the  next  day. 

Experiment  XXXVI.  In  a snail,  whose  heat  was  at  44°,  it  sunk, 
after  it  had  been  put  into  the  cold  mixture,  to  31°,  and  then  the 
animal  froze. 

Experiment  XXXVII.  Several  leeches  having  been  put  into  a 
bottle,  and  the  bottle  immersed  in  the  cold  mixture,  the  ball  of  the 
thermometer  being  placed  in  the  middle  of  them,  the  quicksilver 
sunk  to  31°;  and  by  continuing  the  immersion  for  a sufficient  time 
to  destroy  life,  the  quicksilver  rose  to  32°,  and  then  the  leeches 
froze.  In  all  these  experiments  the  animals  when  thawed  were 
found  dead. 

Finding  that  animals  of  the  imperfect  classes  will,  without  life 
being  totally  extinguished,  admit  of  their  heat  being  reduced  to  that 
point  at  which  the  dead  solids  and  fluids  freeze,  but  if  sunk  much 
below  that,  death  must  be  the  consequence,  I wished  therefore  to 
be  able  to  determine  to  what  degree  the  heat  of  the  animal  could 
be  raised. 


172 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Experiment  XXXVIII.  A healthy  viper  was  placed  in  an  atmo- 
sphere heated  to  108°,  and  allowed  to  stay  seven  minutes;  when 
the  heat  of  the  animal  in  the  stomach  and  anus  W'as  found  to  be 
925°;  beyond  which  it  could  not  be  raised  in  the  above  state  of  the 
atmosphere.  The  same  experiment  was  made  upon  frogs,  with 
nearly  the  same  result. 

Experiment  XXXIX.  An  eel,  very  weak,  its  heat  at  44°,  which 
was  nearly  that  of  the  atmosphere,  was  put  into  water  heated  to 
65°,  for  fifteen  minutes  ; and,  upon  examination,  it  was  found  of  the 
same  degree  of  heat  with  the  water. 

Experiment  XL.  A tench,  whose  heat  was  41°,  was  put  into 
water  at  65°,  and  left  there  ten  minutes;  the  ball  of  the  thermome- 
ter being  introduced  both  into  the  stomach  and  rectum,  the  quick- 
silver rose  to  5.5°.  These  experiments  were  repeated  with  nearly 
the  same  result. 

To. determine  whether  life  had  any  power  of  resisting  heat  and 
cold  in  inferior  classes  of  animals,  I made  eomparative  trials 
between  living  and  dead  ones. 

Experiment  XLl.  1 took  a living  and  a dead  tench,  and  a living 
and  a dead  eel,  and  put  them  into  w'arm  water;  they  all  received 
heat  equally  fast : and  when  they  were  exposed  to  cold,  both  the 
living  and  the  dead  admitted  the  cold  likewise  with  equal  quickness. 

I had  long  suspected  that  the  principle  of  life  was  not  wholly 
confined  to  animals,  or  animal  substance  endowed  with  visible 
organization  and  spontaneous  motion ; but  supposed  that  the  same 
principle  might  exist  in  animal  substances,  devoid  of  apparent 
organization  and  motion,  when  the  power  of  preservation  was 
simply  required. 

I W'as  led  to  this  opinion  about  twenty  years  ago,  when  busied  in 
making  drawings  of  the  grov/th  of  the  chick  in  the  process  of  incu- 
bation. I then  observed,  that  whenever  an  egg  was  hatched,  the 
yolk  (which  is  not  diminished  in  the  time  of  incubation)  was 
always  perfectly  sw'eet  to  the  very  last ; and  that  the  part  of  the 
albumen,  which  has  not  been  expended  on  the  growth  of  the 
animal,  some  days  before  hatching,  was  also  perfectly  sweet, 
although  both  were  kept  in  a heat  of  103°  in  the  hen’s  egg  for 
three  weeks,  and  in  the  duck’s  for  four;  but  I observed  that  if  an 
egg  was  not  hatched,  that  egg  became  putrid  in  nearly  the  same 
time  w'ith  any  other  dead  animal  matter. 

To  determine  from  other  tests  how  far  eggs  possessed  a living 
principle,  I made  the  following  experiments. 

Experiment  XLII.  After  having  placed  an  egg  in  a cold  about  0, 
till  it  froze,  I allowed  it  to  thaw ; by  which  process  it  was  to  be 
supposed  the  preserving  powers  of  the  egg  must  be  destroyed.  I 
then  put  this  egg  into  the  cold  mixture,  and  with  it  one  newly 
laid,  and  found  the  difference  in  freezing  was  seven  minutes  and  a 
half,  the  fresh  one  so  much  longer  time  resisting  the  powers  of 
cold. 

Experiment  XLIII.  A new  laid  egg  being  put  into  a cold  atmo- 


ON  ANIMALS  PRODUCING  HEAT, 


173 


sphere,  fluctuating  between  17°  and  15°,  took  above  half  an  hour 
to  freeze ; but  when  thawed  and  put  into  an  atmosphere  at  25°,  it 
froze  in  half  the  time.  This  experiment  was  repeated  frequently 
witli  nearly  the  same  result. 

To  ascertain  the  comparative  degree  of  heat  between  a living 
and  a dead  egg;  and  also  to  determine  whether  a living  egg  be 
subject  to  the  same  laws  with  the  more  imperfect  animals,  I made 
the  following  experiments. 

Experiment  XLIV.  A fresh  egg,  and  one  which  had  been  frozen 
and  thawed,  were  put  into  the  cold  mixture  at  15°:  the  tlniwed 
one  soon  came  to  32°,  and  began  to  swell  and  congeal;  the  fresh 
one  sunk  to  29i°,  and  in  twenty-five  minutes  later  than  the  dead 
one  it  rose  to  32°,  and  began  to  swell  and  freeze. 

In  this  experiment  the  effect  on  the  fresh  egg  was  similar  to  that 
produced  on  the  frog,  eel,  snail,  &c.,  where  life  allowing  the  heat 
to  be  diminished  two  or  three  degrees  below  the  freezing  point, 
afterwards  resisted  all  further  decrease ; .but  the  powers  of  life 
being  expended  by  this  exertion,  the  parts  froze  like  any  other  dead 
animal  matter. 

From  these  experiments  it  appears  that  a fresh  egg  has  the 
power  of  resisting  heat,  cold,  and  putrefaction  in  a degree  equal  to 
many  of  the 'more  imperfect  animals;  and  it  is  more  than  probable 
this  power  arises  from  the  same  principle  in  both. 

From  the  circumstance  of  those  imperfect  animals  (upon  which 
I made  my  experiments)  varying  their  heat  so  readily,  W'e  may 
conclude  that  heat  is  not  so  very  essential  to  life  in  them  as  in  the 
more  perfect ; although  it  be  essential  to  many  of  the  opei’ations,  or 
what  may  be  called  the  secondary  actions  of  life,  such  as  digesting 
food*  and  propagating  the  species,  both  which,  especially  the  last, 
requiring  the  greatest  powers  an  animal  can  exert.  The  animals 
which  \ve  call  imperfect  being  chiefly  employed  in  the  .act  of 
digestion,  we  may  suppose  their  degree  of  heat  to  be  only  wbat  that 
action  requires  ; it  not  being  essentially  necessary  for  the  life  of  the 
animal  that  heat  should  ever  rise  so  high  in  them  as  to  call  forth 
the  powers  necessary  for  the  propagation  of  the  species.f  When- 

* How  far  this  idea  holds  good  with  fishes,  I am  not  certain. 

I The  hedgehog  may  be  called  a truly  torpid  animal  ; and  we  find  that  its 
actual  heat  is  diminished  when  the  actions  are  not  vigorous. From  a general 


a [The  experiments  by  which  this  important  fact  was  established  are  those 
numbered  I.  and  ‘ll.,  page  IGb.  They  were  made  after  the  publication  of  the 
original  memoir  in  the  Philosophical  Transactions,  in  which  the  note  consequently 
commences  thus:  “ How  far  the  animal  heat  is  lowered  in  the  more  perfect 
animals,  when  these  secondary  actions  are  not  necessary,  as  in  the  bat,  hedgehog, 
bear,  &c.,  I have  not  been  able  to  determine,  not'having  the  opportunities  of  ex- 
amining these  animals.  Dormice  are  in  a mixed  state,  between  the  voluntary, 
and  involuntary,  and  we  find  the  heat  diminished  when  the  actions  are  not  vigor- 
ous; and,  from  a general  review  of  this  whole  subject,  it  would  appear  that  a 
certain  degree  of  heat  in  the  animal  is  necessary  for  digestion,  and  that  necessary 
beat  will  be  according  to  the  nature  of  the  animal.” — FAi/.  Trans,  1778,  p.  91. 

16* 


174 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


ever  therefore  these  imperfect  animals  are  exposed  to  a cold  so 
great  as  to  weaken  their  powers,  and  disable  them  from  performing 
the  first  of  these  secondary  actions,  they  in  some  measure  cease  to 
be  voluntary  agents,  and  remain  in  a torpid  state  during  that 
extreme  degree  of  cold  which  always  occurs  during  some  part  of 
the  winter  in  the  countries  they  inhabit ; and  the  food  of  such 
animals  not  being  in  general  produced  in  the  cold  season  is  a reason 
why  this  torpidity  becomes  in  some  measure  necessary.’*' 

From  the  heat  of  such  animals  sinking  to  the  freezing  point,  or 
even,  lower,  and  then  becoming  stationary,  and  the  animal  not 
being  able  to  support  life  in  a much  greater  degree  of  cold  for  any 
length  of  time,  we  see  a reason  why  they  should  always  endeavour 
to  procure  places  of  abode  in  the  winter  where  the  cold  seldom 
sinks  to  that  point.  We  find  toads  burrowing,  frogs  living  under 
large  stones,  snails  seeking  shelter  under  stones  and  in  holes,'  and 
fishes  having  recourse  to  deep  water  ; the  heat  of  all  those  places 
being  generally  above  the  freezing  point  even  in  our  hardest  frosts ; 
which  are  however  sometimes  so  severe  as  to  kill  many  whose 
habitations  are  not  well  chosen. 

When  the  frost  is  more  intense  and  of  longer  standing  than 
common,  or  in  countries  where  the  winters  are  always  severe, 
there  is  generally  snow  on  the  ground,  and  the  water  freezes:  the 
advantage  arising  from  these  two  circumstances  is  great ; the  snow 
serving  as  a blanket  to  the  earth,  and  the  ice  to  the  water.f 

review  of  this  whole  subject  it  would  appear  that  a certain  degree  of  heat  in  the 
animal  is  necessary  for  its  various  oeeonomical  operations,  among  which  is  di- 
gestion ; and  that  necessary  heat  will  be  according  to  the  nature  of  the  animal, 
and,  probably,  the  nature  of  the  operations  to  be  performed.  A frog  will  digest 
food  when  its  heat  is  at  60°,  but  not  when  at  35°  or  40°  ; and  it  is  very  probable 
that,  when  the  heat  of  the  bear,  hedgehog,  dormouse,  bat,  &c.,  is  reduced  to  70°, 
75°,  or  80°,  they  lose  their  power  of  digestion  ; or  rather  that  the  body,  in  such 
a degree  of  cold,  has  nocall  upon  the  stomach.  That  animals  in  acertain  degree 
of  heat  must  always  have  food  is  further  illustrated  by  the  instance  of.bees.  The 
construction  of  a bee  is  very  similar  to  that  of  a fly,  a wasp,  &c.  A fly  and  a 
wasp  can  allow  their  heat  to  diminish,  as  in  the  fish,  snake,  &c.,  w'ithout  losing 
life,  but  a bee  cannot;  therefore  a bee  is  obliged  to  keep  up  its  heat  as  high  as 
what  we. call  its  digestive  heat,  but  not  its  propagating  ; for  which  purpose  they 
provide  against  such  cold  as  would  deprive  them  even  of  their  digestive  heat,  if 
they  had  not  food  to  preserve  it. 

* The  torpidity  induced  by  cold  in  hybernating  animals  is  unlike  that  which  is 
similarly  induced  in  non-hybernating  animals ; in  the  former  it  is  an  action  of 
preservation,  in  the  latter  one  of  destruction.  See  the  paper  before  quoted,  by 
Dr.  Marshall  Hall.] 

f Snow  and  ice  are  perhaps  the  worst  conductors  of  heat  of  any  substance  yet 
known.  In  the  first  place,  they  never  allow  their  own  heat  to  rise  above  the 
freezing  point,  so  that  no  heal  can  pass  through  ice  or  snow  when  at  33°,  by 
which  means  they  become  an  absolute  barrier  to  all  heat  that  is  at  or  above  that 
degree ; hence  the  heat  of  the  earth,  or  whatever  substance  they  cover,  is  retained  ; 
but  they  are  conductors  of  heat  below  32°.  Perhaps  that  power  decreases  in  pro- 
portion as  the  heat  decreases, under  that  point. 

In  the  winter  1776,  a frost  coming  on,  the  surface  of  the  ground  was  frozen  ; 
but  a considerable  fall  of  snow  fell,  and  continued  several  weeks  : the  heat  of  the 
atmosphere  during  the  time  was  often  at  15° ; but  so  little  did  the  frost  affect  the 


ON  ANIMALS  PRODUCING  HEAT,. 


176 


As  all  the  experiments  I ever  made  upon  the  freezing  of  animals 
(with  a view  to  see  if  it  were  possible  to  restore  the  actions  of  life 
when  thawed)  w'ere tried  upon  whole  ones;  as  I never  saw  life  return 
by  thawing,*  and  wished  to  see  how  far  parts  were  similar  to  the 
whole  in  this  respect,  it  being  asserted,  and  with  some  authority, 
that  parts  of  a man  may  be  frozen,  and  afterwards  recover, — I 
made,  for  this  purpose  the  following  experiments  upon  an  animal 
of  the  same  class  as  ourselves. 

In  January  1777,  I mixed  salt  and  ice  till  the  cold  was  about  0 ; 
in  the  side  of  the  vessel  was  a hole,  through  which  I introduced 
the  ear  of  a rabbit ; and,  to  carry  off  the  heat  as  fast  as  possible,  it 
was  held  between  two  flat  pieces  of  iron  that  went  further  into 
the  mixture.  That  part  of  the  ear  projecting  into  the  vessel  became 
stiff,  and  when  cut  did  not  bleed  ; the  part  divided  by  the  scissors 
flying  from  between  the  blades  like  a hard  chip. 

The  ear  having  remained  in  the  mixture  nearly  an  hour,  soon 
thawed  when  taken  out,  began  to  bleed,  and  became  so  very  flaccid, 
as  to  double  upon  itself,  from  losing  its  natural  elasticity.  When 
out  of  the  mixture  nearly  an  hour,  it  became  warm  : and  this 
warmth  increasing  to  a considerable  degree,  it  also  began  to 
thicken,  in  consequence  of  inflammation,  while  the  other  ear  con- 
tinued in  its  usual  degree  of  cold.  The  day  following  the  frozen 
ear  was  still  warm ; and  even  two  days  after  retained  its  heat  and 
thickness,  which  continued  for  many  days  after. 

About  a week  after  this,  the  mixture  being  the  same  as  in  the 
former  experiment,  I introduced  the  ears  of  the  same  rabbit  through 
the  hole,  and  froze  them  both : the  sound  one  however  froze  first 
probably  from  its  being  considerably  colder  at  the  beginning.  When 
withdrawn  they  soon  thawed,  both  soon  became  warm,  and  the 
fresh  ear  thickened  as  the  other  had  done'  before. 

Such  a change  in  the  parts  does  not  always  take  place  so  quickly; 

ground  underneath  that  the  surface  of  the  ground  thawed,  and  the  earth  retained 
the  heat  of  34°,  in  which  beans  and  peas  will  grow. 

The  same  thing  took  place  in  a pond  where  the  water  was  frozen  on  the  sur- 
face to  a considerable  thickness : a large  quantity  of  snow  having  fallen,  and  co- 
vered the  ice,  the  heat  of  the  water  was  preserved  ; the  ice  thawed,  and*the  snow, 
at  its  under  surface,  was  found  mixed  with  the  water. 

The  heat  of  the  water  under  the  snow  was  at  35°,  in  which  fishes  lived  very 
well. 

It  would  be  an  attempt  worthy  the  attention  of  the  public  philosopher  to 
investigate  the  cause  of  the  heat  of  the  earth,  upon  what  principle  it  is  pre- 
served, &c. 

* Vide  Phil.  Trans,  for  the  year  1775,  vol.  Ixv.  part  ii.  p.  446.® 


® That  animals,  lower  in  in  the  scale  than  any  which  Hunter  experimented 
on  with  this  view,  may,  after  having  been  frozen,  recover  life  by  thawing,  is 
rendered  at  least  highly  probable  from  the  following  statement  by  Rudolphi. 
In  his  description  of  the  Filaria  capsularia,  he  observes,  “ Vermis  vitte  satis  tenax 
est,  ut  per  octiduum  in  frigida  conservaverim,  et  Filarias  in  Harengis  congelatis 
rigidas  et  glacie  tectas  frigida  aflfusa  reviviscere  viderim.”  {Hist.  Entoz., 
vol.  ii.,  p.  62. 


176 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


for  on  repeating  the  experiment  on  the  ear  of  another  rabbit  till  it 
became  as  hard  as  a board,  it  was  found  to  be  longer  in  thawing 
than  in  the  former  experiment,  and  much  longer  before  it  became 
warm  ; in  two  hours,  however,  it  had  acquired  some  degree  of 
warmth,  and  on  the  day  following  was  hot  and  thickened. 

•In  the  spring,  1776,  I perceived  that  my  cocks  in  the  country 
had  their  combs  smooth,  with  an  even  edge,  and  not  so  broad  as 
formerly,  appearing  as  if  near  one  half  of  them  had  been  cut  off. 
Having  inquired  into  the  cause  of  this,  my  servant  told  me  that  it 
had  happened  in  that  winter  during  the  hard  frost,  he  having  then 
observed  that  the  combs  had  in  part  dropped  oft’,  also  that  the  comb 
of  one  cock  had  entirely  separated : but  this  I did  not  see  as  by  ac- 
cident he  was  burnt  to  death.  I naturally  imputed  this  eftect  to  the 
combs  having  been  frozen  to  so  great  a degree  during  the  severe 
weather  as  to  have  the  life  of  the  part  destroyed.  To  determine, 
therefore,  by  experiment,  the  solidity  of  this,  reasoning,  I made  the 
following  experiment. 

I selected  for  tlie  purpose  a very  large  young  cock,  having  a comb 
of  considerable  breadth,  with  deep  serrated  edges,  the  processes  of 
which  were  full  halfan  inch  long.  My  attempts  to  freeze  the  sub- 
stance of  the  comb  did  not  succeed  ; for  that,  being  thick  and  warm, 
resisted  the  effects  of  the  cold,  and  only  the  serrated  edges  were 
frozen.  The  frozen  parts  became  white  and  hard,  and  when  I cut  off 
a little  bit  did  not  bleed,  nor  did  the  animal  show  any  signs  of  pain. 
I next  immersed  in  the  cold  mixture  one  of  his  wfittles,  which  was 
very  broad  and  thin  ; it  froze  very  readily  ; and  upon  thawing  both 
the  comb  and  wattle  they  became  warm,  but  of  a purple  colour, 
having  lost  that  transparency  which  remained  in  the  other  parts 
of  the  comb  and  in  the  other  wattle.  The  wound  in  the  comb  now 
bled  freely. 

Both  comb  and  wattle  recovered  perfectly  in  about  a month. 
The  natural  colour  returned  first  nearest  to  the  sound  parts,  in- 
creasing gradually  till  the  whole  had  acquired  a healthy  appearance. 

There  was  a very  material  difference  in  the  effect  between  those 
fowls,  the  serrated  edges  of  whose  combs  I suspected  to  have  been 
frozen  in  the  winter  of  1775-6,  for  they  must  have  dropped  off. 
The  only  way  in  which  I can  account  for  this  difference  is,  that  in 
those  fowls  the  parts  were  kept  so  long  frozen  that  the  unfrozen  or 
active  parts  had  time  to  inftame,  and  had  brought  about  a separa- 
tion of  the  frozen  parts,  treating  them  exactly  as  dead,  similar  to  a 
mortified  part;  and  that  before  they  thawed,  the  separation  was  so 
far  completed  as  to  deprive  them  of  further  support. 

As  it  is  confidently  asserted  that  fishes  are  often  frozen,  and  again 
return  to  motion,  and  as  I had  never  succeeded  in  any  of  my  trials 
of  the  kind  upon  whole  fishes,  I made  some  experiments  upon  par- 
ticular parts,  to  which  I was  led  by  having  found  a material  dif- 
ference in  the  result  of  experiments  made  upon  the  wdiole,  and  on 
parts  of  the  more  perfect  animals. 

I froze  the  tail  of  a tench,  as  high  as  the  anus,  which  became  as 


ON  THE  HEAT  OF  VEGETABLES. 


177 


hard  as  a board  : when  thawed,  that  part  was  whiter  than  common  ; 
and  when  it  moved,  the  whole  tail  moved  as  one  piece,  and  the  ter- 
mination of  the  frozen  part  appeared  like  the  joint  on  which  it  moved. 

On  the  same  day  I froze  the  tails  of  two  gold  fishes  till  they  be- 
came as  solid  as  a piece  of  wood.  They  were  put  into  cold  water 
to  thaw,  and  appeared  for  some  days  to  be  very  well;  but  that  part 
of  the  tails  which  had  been  frozen  had  not  the  natural  colour,  and 
the  fins  of  the  tails  became  ragged.  About  three  weeks  after,  a fur 
came  all  over  the  frozen  parts;  their  tails  became  lighter,  so  that 
the  fishes  were  suspended  in  the  water  perpendicularly;  they  had 
almost  lost  the  power  of  motion  ; and  at  last  died.  The  water  in 
which  they  were  kept  was  New  River  water,  shifted  every  day, 
and  in  quantity  about  ten  gallons. 

I made  similar  experiments  upon  an  order  of  animals  still  inferior, 
viz.  common  earth-worms. 

I first  froze  the  whole  of  an  earth-worm  as  a standard  ; when 
thawed  it  was  perfectly  dead. 

I then  froze  the  anterior  half  of  another  earth-worm ; but  the 
whole,  died. 

I next  froze  the  posterior  half  of  an  earth-worm  ; the  anterior 
half  continued  alive,  and  separated  itself  from  the  dead  part. 

From  some  of  these  experiments  it  appears  that  the  more  imper- 
fect animals  are  capable  of  having  their  heat  and  cold  varied  very 
considerably,  but  not  according  to  the  degree  of  heat  or  cold  of  the 
surrounding  medium  in  which  they  can  support  life;  for  they  can 
live  in  a cold  considerably  below  the  freezing  point,  and  yet  the 
living  powers  of  the  animal  will  not  allow  their  heat  to  be  diminished 
much  beyond  32°.  Whenever  the  surrounding  cold  brings  them  so 
low,  the  power  of  generating  heat  takes  place ; and  if  the  cold  is 
continued,  the  animals  exert  this  power  till  life  is  destroyed  ; after 
which  they  freeze,  and  are  immediately  capable  of  admitting  any 
degree  of  cold. 


15.  EXPERIMENTS  AND  OBSERVATIONS  ON  VEGE- 
TABLES, WITH  RESPECT  TO  THE  POWER  OF 
PRODUCING  HEAT.* 

To  ascertain  whether  vegetables  could  be  frozen,  and  afterwards 
retain  all  their  properties  when  thawed,  or  had  the  same  power  of 
generating  heat  with  animals,  I made  several  experiments.  Vege- 
table juices  when  squeezed  out  of  a green  plant,  such  as  cabbage 
and  spinage,  froze  in  a cold  of  about  29°;  and  between  29°  and  30° 

* [This  paper  includes  those  portions  of  the  two  communications  to  the  Royal 
Society,  On  the  Heat  of  Animals  and  Vegetables,  which  were  omitted  by  Hunter 
in  the  ‘ Animal  (Economy.’  See  Phil.  Trans.,  Ixv.,  1785,  p.  450.]  , 


17S 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


thawed  again,  which  is  about  4°  abov^e  the  point  at  which  the  animal 
juices  freeze  and  thaw. 

Experiment  I.  I took  a young  growing  bean,  about  three  inches 
long  in  the  stalk,  and  put  it  into  the  leaden  vessel  with  common 
water,  and  then  immersed  the  whole  into  the  cold  mixture.  The 
water  very  soon  froze  all  around  it ; however,  the  bean  itself  took 
up  a longer  time  in  freezing  than  the  sarhe  quantity  of  water  w'ould 
have  done;  yet  it  did  freeze,  and  was  afterwards  thawed  and 
planted  in  the  ground,  but  it  soon  withered.  The  same  experi- 
ment was  made  upon  the  bulbous  roots  of  tulips,  and  with  the  same 
success. 

Experiment  II.  A young  Scotch  fir,  which  had  two  complete 
shoots  and  a third  growing,  and  which  consequently  w'as  in  its 
third  year,  was  put  into  the  cold  mixture,  which  was  between  15° 
and  17°.  The  last  shoot  froze  with  great  difficulty,  which  appeared 
to  be  owing  in  some  measure  to  the  repulsion  between  the  plant 
and  the  water.  When  thawed  the  young  shoot  was  found  flaccid. 
It  was  planted ; the  first  and  second  shoot  we  found  retained  life, 
while  the  third,  or  growing  shoot,  withered. 

Experiment  III.  A young  shoot  of  growing  oats,  with  three 
leaves,  had  one  of  the  leaves  put  into  the  cold  mixture  at  22°,  and 
it  soon  was  frozen.  The  roots  were  next  put  in,  but  did  not  freeze; 
and  when  put  into  the  ground  the  whole  grew,  excepting  the  leaf 
which  had  been  frozen.  The  same  experiment  was  made  upon 
the  leaves  and  roots  of  a young  bean,  and  attended  with  the  same 
success. 

Experiment  IV.  A leaf  taken  from  a growing  bean  was  put  into 
the  cold  mixture  and  frozen,  and  afterwards  thawed,  which  served 
as  a standard.  Another  fresh  leaf  was  taken  and  bent  in  the 
middle  upon  itself;  a small  shallow  leaden  vessel  was  put  upon  the 
top  of  the  cold  mixture,  and  the  two  leaves  put  upon  its  bottom  ; 
but  one. half  of  each  leaf  was  not  allowed  to  touch  the  vessel  by  the 
bend  : the  cold  mixture  was  between  17°  and  15°,  and  the  atmo- 
.sphere  at  22°.  The  surfaces  of  the  two  leaves  which  were  in  con- 
tact with  the  lead  were  soon  frozen  in  both ; but  those  surfaces 
which  rose  at  right  angles,  and  were  therefore  only  in  contact  with 
the  cold  atmosphere,  did  not  freeze  in  equal  times;  the  one  that  had 
gone  through  this  process  before  froze  much  sooner  than  the  fresh 
one.  The  above  experiment  was  repeated  when  the  cold  mixture 
was  at  25°,  24°,  and  the  atmosphere  nearly  the  same,  and  with  the 
same  success  ; only  the  leaves  were  longer  in  freezing,  especially 
the  fresh  leaf. 

Experiment  V.  The  vegetable  juices  above-mentioned  being 
frozen  in  the  leaden  vessel,  tbe  cold  mixture  at  28°,  and  the  atmo- 
sphere the  same,  a growing  fir-shoot  was  laid  upon  the  surface, 
also  a bean-leaf ; and  upon  remaining  there  some  minutes,  they 
were  found  to  have  thawed  the  surface  on  which  they  lay.  This 
I thought  might  arise  from  the  greater  warmth  of  these  substances 
at  the  time  of  application  ; but  by  moving  the  fir-shoot  to  another 
part,  we  had  the  same  effect  produced. 


ON  THE  HEAT  OF  VEGETABLES. 


179 


Experiment  VI.  A fresh  leaf  of  a bean  was  exactly  weighed  ; 
it  was  then  put  into  the  cold  atmosphere  and  frozen.  In  this  state 
it  was  put  back  into  the  same  scale,  and  allowed  to  thaw.  No 
alteration  in  the  weight  was  produced. 

From  the  foregoing  experiments  it  appears,  first,  that  plants, 
when  in  a state  of  actual  vegetation,  or  even  in  such  a state  as  to 
be  capable  of  vegetating  under  certain  circumstances,  must  be  de- 
prived of  their  principle  of  vegetation  befoye  they  can  be  frozen. 
Secondly,  vegetables  have  a power  within  themselves  of  producing 
or  generating  heat;  but  not  always  in  proportion  to  the  diminution 
of  heat  by  application  of  cold,  so  as  to  retain  at  all  times  an  uni- 
form degree  of  heat;  for  the  internal  temperature  of  vegetables  is 
susceptible  of  variations  to  a much  greater  extent  indeed  than  that 
of  the  more  imperfect  animals,  but  still  within  certain  limits  : be- 
yond these  limits  the  principle  of  vegetable,  as  of  animal  life,  resists 
any  further  change.  Thirdly,  the  heat  of  vegetables  varies  ac- 
cording to  the  temperature  of  the  medium  in  which  they  are,  which 
we  discover  by  varying  that  temperature,  and  observing  the  heat 
of  the  vegetable.  Fourthly,  the  expense  of  the  vegetating  powers 
in  this  case  is  proportioned  to  the  necessity,  and  the  whole  vegetable 
powers  may  be  exhausted  in  this  way.  Fifthly,  this  power  is  most 
probably  in  proportion  to  the  perfection  of  the  plant,  the  natural 
heat  proper  to  each  species,  and  the  age  of  each  individual.  It 
may  also  perhaps  depend,  in  some  degree,  on  other  circumstances 
not  hitherto  observed  ; (for  in  Experiment  II.  the  old  shoot  did  not 
lose  its  powers,  while  that  which  was  young  or  growing  did  ; and 
in  Experiments  II.  andllLiXye  found  that  the  young  growing  shoot 
of  the  fir  was  with  great  difficulty  frozen  at  15°,  while  a bean-leaf 
was  easily  frozen  at  22°;  and  in  experiment  V.  the  young  shoot  of 
fir  thawed  the  ice  at  28°  much  faster  than  the  leaf  of  the  bean. 
Sixthly,  it  is  probably  by  means  of  this  principle  that  vegetables 
are  adapted  to  different  climates.  Seventhly,  that  suspension  of 
the  functions  of  vegetable  life,  which  takes  place  during  the  winter 
season,  is  probably  owing  to  their  being  susceptible  of  such  a great 
variation  of  internal  temperature,  , Eighthly,  the  roots  of  vegetables 
are  capable  of  resisting  cold  more  than  the  stem  or  leaf ; therefore, 
though  the  stem  be  killed  by  cold,  the  root  may  be  preserved,  as 
daily  experience  evinces.  The  texture  of  vegetables  alters  very 
much  by  the  loss  of  life,  especially  those  .which  are  watery  and 
young  ; from  being  brittle  and  crisp,  they  beconie  tough  and  flexi- 
ble. The  leaf  of  a bean  when  in  full  health  is  thick  and  mossy, 
repels  water  as  if  greasy,  and  will  often  break  before  it  is  consider- 
ably bent ; but  if  it  is  killed  slowly  by  cold,  it  will  lose  all  these 
properties,  becoming  then  pliable  and  flaccid  : deprived  of  its  power 
of  repelling  tvater,  it  is  easily  made  .wet,  and  appears  like  boiled 
greens.'  . If  killed  quickly  by  being  frozen  immediately,  it  will  re- 
main in  the  same  state  as  when  alive;  but  upon  thawing,  will  im- 
mediately lose  all  its  former  texture.  This  is  so  remarkable,  that 
if  wbuM  ihduce  one'  to  believe  that  it  lost  considerably  of  its  sub- 

■ M ...  I - 


180 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


Stance ; but  from  Experiment  VI.  it  is  evident  that  it  does  not. 
The  same  thing  happens  to  a plant  when  killed  by  electricity.*  If 
a growing  juicy  plant  receives  a stroke  of  electricity  sufficient  to 
kill  it,  its  leaves  droop,  and  the  whole  becomes  Hexible. 

So  far  animal  and.  vegetable  life  appear  to  be  the  same  ; yet  an 
animal  and  a vegetable  differ  in  one  very  material  circumstance, 
which  it  may  be  proper  to  lake  particular  notice  of  in  this  place, 
as  it  shows  itself  with  remarkable  evidence  in  these  experiments. 
An  animal  is  equally  old  in  all  its  parts,  excepting  where  new  parts 
are  formed  in  consequence  of  diseases  ; and  we  find  that  these  new 
or  young  parts  in  animals,  like  the  young  shoots  of  vegetables,  are 
not  able  to  support  life  equally  with  the  old  ; but  every  plant  has  in 
it  a series  of  ages.  According  to  its  years,  it  has  parts  of  all  the 
successive  ages  from  its  first  formation ; each  part  having  power 
equal  to  its  age,  and  each  part,  in  this  respect,  being  similar  to  ani- 
mals of  so  many  different  ages.  Youth,  in  all  cases,  is  a state  of 
imperfection ; for  we  find  that  few  animals  that  come  into  the 
world  in  winter  live,  unless  they  are  particularly  taken  care  of  ; 
and  we  may  observe  the  same  of  vegetables.  I found  that  a young 
plant  was  more  easily  killed  than  an  old  one;  as  also  the  youngest 
part  of  the  same  plant. 

fAs  1 had  formerly,  in  making  my  experiments  upon  animals 
relative  to  heat  and  cold,  made  similar  ones  on  vegetables,  and 
had  generally  found  a great  similarity  between  them  in  these 
respects,  I was  led  to  pursue  the  subject  on  the  same  plan ; but  I 
was’  still  further  induced  to  continue  my  experiments  upon  vege- 
tables, as  I imagined  I saw  a material  difference  between  them  in 
their  power  of  supporting  cold. 

From  observations  and  the  foregoing  experiments,  it  plainly  ap- 
pears that  the  living  principle  will  not  allow  the  heat  of  such  animals 
to  sink  much  lower  than  the  freezing  point,  although  the  surround- 
ing atmosphere  be  much  colder,  and  that  in  such  a state  they 
cannot  support  life  long ; but  it  may  be  observed,  that  most  vege- 
tables of  every  country  can  sustain  the  cold  of  their  clinqate.  In 
very  cold  regions,  as  in  the  more  northern  parts  of  America,  where  the 
thermometer  is  often  50°  below  0,  where  people’s  feet  are  known 
to  freeze  and  their  noses  to  drop  off  if  great  care  be  not  taken,  yet 
the  spruce-fir,  birch,  juniper,  &c.,  are  not  affected. 

Yet,  that  vegetables  can  be  affected  by  cold,  daily  experience 
evinces  ; for  the  vegetables  of  every  country  are  affected  if  the 
season  be  more  than  ordinarily  cold  for  that  country,  and  some 
more  than  others ; for  in  the  cold  climates  above  mentioned  the 
life  of  the  vegetable  is  often  obliged  to  give  way  to  the  cold  of  the 
country  : a tree  shall  die  by  the  cold  ; then  freeze  and  split  into  a 
great  number  of  pieces ; and  in  so  doing  produce  considerable  noise, 
giving  loud  cracks,  which  are  often  heard  at  a great  distance. 

♦ To  kill  a whole  plant  by  electricity,  it  is  necessary  to  apply  the  conductor, 
or  give  a shock  to  every  projecting  part;  for  any  part  that  is  out  of  the  line  of 
direction  will  still  retain  life. 

t [See  Phil.  Trans., Ixviii.,  1778,  p.  38.] 


ON  THE  HEAT  OF  VEGETABLES. 


181 


In  this  country  the  same  thing  sometimes  happens  to  exotics 
from  warmer  climates.  A remarkable  instance  of  this  kind  hap- 
pened this  winter  in  His  Majesty’s  garden  at  Kew.  The  Erica 
arborea,  or  tree-heath,  a native  of  Spain  and  Portugal,  which  had 
kept  its  health  extremely  well,  against  a garden  wall  for  four  or 
five  years,  though  covered  with  a mab  was  killed  by  the  cold,  and 
then,  being  frozen,  split  into  innumerable  pieces.*  But  the  ques- 
tion is,  Is  ev'ery  tree  dead  that  is  frozen  ? I can  only  say,  that  in 
all  the  experiments  I ever  made  upon  trees  and  shrubs,  whether  in 
the  growing  or  active  state,  or  in  the  passive,  that  whole  or  part 
which  was  frozen  was  dead  when  thawed. 

The  winter  1775-6  afforded  a very  favourable  opportunity  for 
making  experiments  relative  to  cold,  which  I cai’efully  availed 
myself  of.  However,  previous  to  that  winter,  I had  made- many 
experiments  upon  vegetables  respecting  their  temperatui'e,  com- 
paratively with  that  of  the  atmosphere,  and  when  they  were  in  their 
different  states  of  activity  ; I therefore  examined  them  in  different 
seasons,  with  a view  to  see  what  powers  vegetables  have.  I shall 
relate  these  experiments  in  the  order  in  which  they  were  made. 

They  were  begun  in  the  spring,  the  actions  of  life  upon  which 
growth  depends  being  then  upon  the  increase  ; and  they  were  con- 
tinued till  those  actions  were  upon  the  decline,  and  also  when  all 
actions  were  at  an  end,  but  whilst  the  passive  powers  of  life  wei’e 
still  retained. 

The  first  were  made  on  a walnut-tree,  nine  feet  high  in  the  stem, 
and  seven  feet  in  circumference  in  the  middle. 

A hole  was  bored  into  it  on  the  north  side,  five  feet  above  the 
surface  of  the  ground,  eleven  inches  deep  towards  the  centre  of 
the  tree,  but  obliquely  upwards,  to  allow  any  sap,  which  might 
ooze  through  the  wounded  surface  to  run  out. 

I then  fitted  to  this  part  a box,  about  eight  inc^ies  wide  and  five 
deep,  and  fastened  it  to  the  tree : the  bottom  of  the  box  opened  like 
a door  with  a hinge.  I stuffed  the  box  with  wool,  excepting  the 
middle,  opposite  to  the  hole  in  the  -tree  ; for  this  part  I had  a plug 
of  wool  to  stuff’  in,  which,  when  the  door  was  shut,  inclosed  the 
whole.  The  intention  of  this  was  to  keep. off,  as  much  as  possible, 
all  immediate  external  influence  either  of  heat  or  cold. 

The  same  thermometer  with  w'hich  I made  my  former  experi- 
ments, seven  inches  and  a half  long,  was -sunk  into  a long  feather 
of  a peacock’s  tail,  with  a slit  upon  one  side  to  show  the  degrees; 

* This  must  be  owing  to  the  sap  in  ffe  tree  freezing,  and  occupying  a larger 
space  when  frozen  than  in  a fluid  state,  similar  to  .water ; and  lhat'there  is  a 
sufficient  quantity  of  sap  in  a tree  newly  killed,  is  proved  by  the  vast  quantity 
that  flows  out  on  wounding  a tree.  But  what  appeared  most  remarkable  to 
me  was,  that  in  a walnut-tree,  on  which  I made  many  of  my  experiments,  I ob- 
served that  more  sap  issued  out  in  the  winter  than  in  the  summer.  In  the  sum- 
mer, a hole  being  bored,  scarcely  any  came  out,  but. in  the  winter  it  flowed  out 
abundantly. 


17  . 


182 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


by  this  means  the  ball  of  the  thermometer  could  be  introduced  into 
the  bottom  of  the  hole. 

Experiment  1.  March  29.  I began  my  experiments  at  six  in 
the  morning,  the  atmosphere  at  57'2°,  the  thermometer  in  the  tree 
at  55°;  when  it  was  withdrawn  the  quieksilver  sunk  to  53,  but 
soon  rose  to  57i°.* 

This  experiment  was  repeated  three  times  with  the  same  success. 
Here  the  tree  was  cooler  than  the  atmosphere,  when  one  should 
rather  have  expected  to  find  it  warmer,  since  it  could  not  be  sup- 
posed to  have  as  yet  lost  its  former  day’s  heat. 

Exp.  II.  April  4th,  half-past  five  in  the  evening.  The  tree  at 
56°,  the  atmosphere  at  62°;  the  tree  therefore  still  cooler  than  the 
atmosphere. 

Exp.  III.  April  5th.  Wind  in  the  north,  a coldish  day,  six 
o’clock  in  the  evening;  the  thermometer  in  the  tree  was  at  55°,  the 
atmosphere  at  47°;  the  tree  warmer  than  the  atmosphere. 

Exp.  IV.  April  7lh,  a cold  day,  wind  in  the  north,  cloudy.  At 
three  in  the  afternoon  the  thermometer  in  the  tree  was  at  42°,  the 
atmosphere  at  42°  also. 

Exp.  V.  April  9th,  a cold  day,  with  snow,  hail,  and  wind  in  the 
north-east.  At  six  in  the  evening  the  thermometer  in  the  tree  at 
45°,  the  atmosphere  at  39°. 

Here  the  tree  was  warmer  than  the  atmosphere,  just  as  might 
have  been  expected.  If  these  experiments  prove  anything,  it  is  that 
there  is  no  standard  ; and  probably  these  variations  arose  from  some 
circumstance  which  had  no  immediate  connexion  with  the  internal 
powers  of  the  tree ; but  it  may  also  be  supposed  to  have  arisen 
from  a power  in  the  tree  to  produce- or  diminish  heat,  as  some  of 
them  were  in  opposition  to  the  atmosphere. 

After  having  ■ endeavoured  to  find  out  the  comparative  heat 
between  vegetables  and  the  atmospliere  when  the  vegetables  were 
in  action,  I next  made  my  experiments  upon  them  when  they  were 
in  the  passive  life. 

As  the  difference  was  very  little  when  in  their  most  active  state, 
I could  expect  but  very  little  when  the  powers  of  the  plant  were  at 
rest. 

From  experiment  upon  the  more  imperfect  classes  of  animals  it 
plainly  appears,  that  although  they  do  not  resist  the  effects  of 
extreme  cold  till  they,  are  brought  to  the  freezing  point,  they  then 
appear  to  have  the  power  of  resisting  it,  and  of  not  allowing  their 
cold  to  be  brought  much  lower. 

To  see  how  far  vegetables  are  similar  to  those  animals  in  this 
respect,  I made  several  experiments:  I however  suspected  them 
not  to  be  similar,  because  such  animals  will  die  in  a cold  in  which 
vegetables  do  live ; I therefore  supposed  that  there  was  some  other 
principle. 

* The  sinking  of  the  quicksilver  upon  being  withdrawn  I imputed  to  the  evapo- 
ating  of  the  moisture  of  the  fluid  upon  the  ball. 


ON  THE  HEAT  OF  VEGETABLES. 


183 


I did  not  confine  these  experiments  to  the  walnut-tree,  but  made 
similar  ones  on  several  trees  of  different  kinds,  as  pines,  yews,  pop- 
lars, &c.,  to  see  what  was  the  difference  in  different  kinds  of  trees. 
The  difference  proved  not  to  be  great,  not  above  a degree  or  two  : 
however,  this  difference,  although  small,  shows  a principle  in  life, 
all  other  things  being  equal ; for  as  the  same  experiments  were 
made  on  a dead  tree,  which  stood  with  its  roots  in  the  ground, 
similar  to  the  living  ones,  they  became  more  conclusive. 

In  October  I began  the  experiments  upon  the  walnut-tree  when 
its  powers  of  action  were  on  the  decline,  and  when  it  was  going 
into  its  passive  life. 

Exp.  VI.  October  18th,  at  half-past  six  in  the  morning,  the  atmo- 
sphere at  51i°,  the  thermometer  in  the  tree  was  at  55i°;  but,  on 
withdrawing  and  exposing  it  for  a few  minutes  in  the  common 
atmosphere,  it  fell  to  50|°. 

Exp.  VII.  October  21st,  seven  o’clock  in  the  morning,  the  atmo- 
sphere at  41°,  tlje  tree  at  47°. 

Exp.  VIII.  October  21st,  in  the  evening  at  five  o’clock,  the 
atmosphere  at  514°,  the  tree  at  57°. 

Exp.  IX.  October  22d,  at  seven  in  the  morning,  the  atmosphere 
at  42°,  the  tree  at  48°. 

Exp.  X.  October  22d,  one  o’clock  afternoon,  the  atmosphere  at 
51°,  the  tree  at  53°. 

Exp.  XL  October  23d,  in  the  evening  of  a wet  day,  the  atmo- 
sphere at  46°,jhe  tree  at  48°. 

Exp.  XII.  October  28th,  a dry  day,  the  atmosphere  at  45°,  the 
tree  at  46°. 

Exp.  XIII.  October  29th,  a fine  day,  the  atmosphere  at  45°,  the 
tree  at  49°. 

Exp.  XIV.  November  2d,  wind  east,  the  atmosphere  at  43°,  the 
tree  at  43°. 

Exp.  XV.  November  5th,  wet  day,  the  atmosphere  at  43°,  the 
tree  at  45°. 

Exp.  XVI.  November  10th.  Atmosphere  at  49°,  the  tree  at  55°. 

Exp.  XVII.  November  18th.  Atmosphere  at  42°,  the  tree  at  44°. 

Exp.  XVIII.  November  20th,  fine  day,  the  atmosphere  at  40°, 
the  tree  at  42°. 

Exp.  XIX.  December  2d.  The  atmosphere  at  54°,  the  tree  at  54°. 

In  all  these  experiments,  which  were  made  at  various  times -in 
the  day,  viz.,  in  the  morning,  at  noon,  and  in  the  evening,  the  tree 
was  in  some  degree  warmer  than  the  atmosphere,  excepting  in  one, 
when  their  temperatures  were  equal.  For  .the  sake  of  brevity,  I 
have  drawn  up  my  other  experiments  (which  were  made  on  dif- 
ferent trees)  into  four  tables,  as  they  were  made  at  four  different 
degrees  of  heat  of  the  atmosphere,  including  those  made  in  the 
lime  of  the  very  hard  frost  in  the  winter  of  1775-6.  They  were 
as  follows : 


184 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


Table  I. 


Atmosphere. 

Names. 

Height. 

Dia- 

meter. 

Heat. 

ft. 

in . 

ft. 

in. 

o 

' Carolina  pop.l a r 

2 

0 

0 

2 

29^ 

English  poplar 

4 

0 

0 

2i 

29i 

Oriental  plane 

• • 

3 

0 

0 

If 

30 

Occidental  plane  . 

3 

6 

0 

2 

30 

Carolina  plane  . ' 

1 

0 

0 

H 

30 

Birch  .... 

3 

6 

0 

n 

29i 

29  deg. 

s; 

Scotch  fir  . . . 

3 

6 

0 

4 

28i 

Cedar  of  Lebanon  . 

2 

2 

0 

28i 

Arbutus 

2 

6 

0 

3i 

30 

Arbor  vitaj 

2 

8 

0 

3i 

29 

Deciduous  cypress 

3 

0 

0 

2i 

30 

Lacker  varnish 

3 

6 

0 

2 

30 

1 

._Walnut-tree  . 

5 

0 

2 

4 

31 

The  old  liole  in  the  walnut  tree,  being  full  of  sap,  was  frozen  up  ; 
but  a new  one  was  made. 


Table  II. 


Atmosphere.  Names. 

Height. 

Dia- 

meter. 

Heat. 

fSpruce  fir  . . ... 

1 Scotch  fir  . 

1 Silver  fir  . 

1 Weymouth  fir  . 

27  deg.  Yew  ..... 

Holly 

Plum-tree  ..... 
Dead  cedar  . . . 

^Ground  under  snow  . 

ft.  in. 

,4  0 

1 5i 

3 11 

4 6 

3 7 

2 6 • 

4 6 
3 11 

0 3 deep. 

* COCOtSWtOtOH-tO-’ 



o 

32 

28 

30 

30 

30 

30 

29 

34 

Table'III. 


Atmosphere. 

Names. 

Heat. 

fSpruce  fir 

O 

23 

1 Scotch  fir 

53 

1 Silver  fir 

23 

24  deg. 

<(  Weymouth  fir  . 

23 

1 Yew 

22 

1 Holly 

23 

bDead  cedar 

24 

The  same  trees  we  mentioned  when  the  thermometer  was'  at  29°, 
in  new  holes  made  at.  the  same  height,  and  left  some  time  pegged 
up  till  the  .heat  produced  by  the  gimlet  was  gone  off;  but  in  which, 
as  they  were  moist  from  the  sap,  the  heat  could  be  very  little, 
especially  as  the  gimlet  Was  not  in  the  least  heated  by  the  opera- 
tion. 


OF  PERSONS  APPARENTLY  DROWNED. 


185 


Table  IV. 


Atmosphere. 

Names. 

Heat. 

rUarolina  poplar 

O 

17 

English  poplar 

17 

Oriental  plane 

17 

16  deg.  -< 

Occidental  plane 

17 

Carolina  plane 

17 

Birch  .... 

17 

i^Seotch  fir  . . . 

. •.  16i 

It  will  be  necessary  to  observe,  that  the  sap  of  the  walnut-tree, 
which  flowed  out  in  great  quantity,  froze  at  32°.  I did  not  try  to 
freeze  the  sap  of  the  others. 

Now  since  the  sap  of  a tree  when  taken  out  freezes  at  32°;  also, 
since  the  sap  of  a tree,  when  taken'out  of  its  proper  canals,  freezes 
when  the  heat  of  the  tree  is  at  31°  ; and  since  the  heat  of  the  tree 
can  be  so  low  as  17°,  Muthout  freezing;  by  what  power  are  the 
juices  of  the  tree,  when  in  their  proper  canals,  kept  fluid  in  such  a 
cold  ? Is  it  the  principle  of  vegetation  ? Or  is  the  sap  inclosed  in 
such  a way  as  that  the  process  of  freezing  cannot  take  place, 
which  we  find  to  be  the  case  when  water  is  confined  in  globular 
vessels?  If  so,  its  confinement  must  be  very- different  from  the 
confinement  of  moisture  in  dead  vegetables  ; but  the  circumstance 
of  vegetables  dying  with  the  cold  and  then  freezing  appears  to 
answer  the  last  question.  These,  however,  are  questions  which  at 
present  I shall  not  endeavo.ur  to  solve. 

I have  made  several  experiments  upon  the  seeds  of  vegetables 
similar  to  those  on  the  eggs  of  animals  ; but  as  inserting  them  would 
draw  out  this  paper  to  too  great  a length,  I will  reserve  them  for 
another. 

10.  PROPOSALS  FOR  THE  RECOVERY  OF  PERSONS 
APPARENTLY  DROWNED.*- 

Having  been  requested  by  a principal  rnember  of  the  society 
established  for  the  recovery  of  persons  apparently  drowned  to  com- 
mit my  thoughts  on  that  subject  to  paper,  I readily  complied, 
hoping,  that  although  I have  had  no  opportunities  of  making  actual 
experiments  upon  drowned  persons,  it  might  be  in  my  power  to 
throw  some  lights  on  a subject  so  closely  connected  with  the  inqui- 
ries which  for  many  years  have  been  my  business  and  favourite 
amusement : I therefore  collected  together  my  observations  and 
experiments  relative  to  the  loss  and  recovery  of  the  actions  of  life, 
which  I now  offer  to  the  public.  The  endeavour  to  recover  per- 

* [From  the  Philosophical  Transactions,  vol.  Ixvi. ; read  March  21,  177G,] 

' 17* 


18G 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


sons  apparently  drowned  is  a new  practice,  and  has  furnished,  as 
yet,  few  important  and  clear  facts:  our  knowledge  of  the  animal 
oeconomy  is  so  imperfect,  that  I am  afraid  our  reasoning  from  that 
alone  must  not  be  relied  on  in  a question  so  interesting  to  the  cause 
of  humanity.  But  let  us  reason  as  well  as  we  can  from  the  few 
data  we  have,  and  let  every  man  bring  forward,  freel}^  the  obser- 
vations he  has  made,  that  the  subject  thus  fairly  before  the 
public  may  in  time,  by  its  united  efforts,  be  more  perfectly  under- 
stood. 

I shall  consider  an  animal  apparently  drowned  as  not  dead,  but 
that  only  a suspension  of  the  actions  of  life  has  taken  place.  The 
difference  between  a suspension  of  the  actions,  of  life  and  absolute 
death  is  w'ell  illustrated  by  the  common  snail  when  drowning.  If  a 
snail  is  immersed  in  water  and  kept  there,  certain  voluntary  and 
instinctive  actions  take  place;  but  after'  remaining  a certain  time 
covered  by  the  water,  all  these  actions  cease.  Hence  the  animal, 
being  relaxed,  naturally  comes  out  of  the  shell  in  that  state;  its 
stomach  is  filled  with  water,  and  the  body  appears  larger’  than 
natural,  but  without  motion.  These  actions  continue  thus  suspend- 
ed till  either  the  cause  of  suspension  be  removed  or  some  other 
stimulus  shall  bring  the  parts  into  action  : but  under  such  circum- 
stances life  cannot  be  preserved  for  any  considerable  length  of  time  ; 
and  when  the  stimulus  which  precedes  death  takes  place,  the  whole 
animal  is  thrown  into  action,  and  in  that  contracted  state,  possibly, 
absolute  death  is  produced.  A state  of  relaxation  should  therefore 
(where  an  universal  violence  has  not  been  committed),  be  considered 
as  the  criterion  of  life;,  and  even  in  such  cases  should  be  for  some 
time  admitted  as  a probable  reason  for  supposing  life  still  to  exist. 

•If  an  animal  appears  so  far  dead  as  to  have  lost  all  the  actions 
characteristic  of  life,  yet  a certain  degree  of  action  in  all  the  parts 
will  be  produced  when  absolute  death  is  taking  place;  and  that 
animal,  being  still  susceptible  of  stimulus,  is  recoverable  if  the 
proper  stimulus  could  be  applied. 

It  is  asserted  that  men  have  recovered  the  actions  of  life  even 
after  the  contraction,  in  consequence  of  the  stimulus  which  pre- 
cedes death,  has  taken  place.  If  this  be  ti’ue,  which  I very  much 
doubt,  the  stimulus  must  first  produce  relaxation,  which  is  an  action 
dependent;  on  life. 

This  is  probably  the  case  in  the  first  appearances  of  death  from 
all  violent  accidents,  except  those  caused  by  lightning,  electricity, 
an  universal  shock,  a blow  on  the  stomach,  a violent  affection  of 
the  mind,  or  some  other  modes  by  which  absolute  death  may  be 
instantaneously  produced,  which  all  appear  to  act  in  the  same  way, 
producing. absolute  and  instant  death.  For  in  cases  which  have 
fallen  under  my  observation,  the  concomitant  circumstances  have 
resembled  those  which  attend  death  caused  by  lightning  or  electri- 
city, such  as  a total  and  instantaneous  privation  of  sense  and  mo- 
tion without  convulsions;  consequently,  no  rigor  of  muscles  having 
been  produced,  and  the  blood  remaining  uncoagulated,  differing 


OF  PERSONS  APPARENTLY  DROWNED. 


187 


entirely  in  these  respects  from  what  appears  in  persons  deprived 
of  sense  and  life  by  any  injury  done  the  brain.  It  seems  only 
possible  to  account  for  this  eflect  of  a blow  on  the  stomach,  from 
the  connexion  subsisting  between  that  viscus  and  every  part  of  the 
body,  at  least  with  vital  parts;  the  blow  most  pi'obably  causing 
instant  death  in  that  organ  of  which  the  death  o-f  the  whole  animal 
is  the  consequence.*  When  death  takes  place  from  violent  affections 
of  the  mind,  it  must  be  referred  to  the  universal  intluence  which  the 
mind  has  over  the  body. 

To  ascertain  when  a body  is  deprived  of  life  it  is  first  necessary 
to  know  in  what  manner  apparent  death  took  place  ; wdiether  in 
the  common  way,  or  from  the  vital  actions  being  too  long  suspended. 
In  either  case  stiffness  of  the  muscles 'is  probably  the  most  certain 
and  most  evident  proof  of  absolute  death,  since  that  arises  from 
the  stimulus  immediately  preceding  death,  having  taken  place.  But 
if  the  privation  of  life  is  produced  by  any  of  the  modes  above  men-^ 
tioned,  which  kill  instantaneously  and  universally,  the  stimulus  which 
produces  stiffness  is  not  allowed  lime  to  act,  and  the  muscles  are 
all  left  in  a relaxed  state.  Yet  this  state  of  relaxation  must  not,  on 
that  account,  be  always  considered  as  a proof  of  life  still  remaining. 

A degree  of  ffaccidit'y  in  the  eyeballs,  which  produces  glassiness, 
is  a certain  mark  of  death  ; but  is,  however,  only  a secondary  mode 
of  ascertaining  it  in  those  instances  where  the.  body  becomes  stiff; 
but  may.be  the  first  mode  where  absolute  death  takes  place  instan- 
taneously ; and  putrefaction  will  be  the>second  ; while  in  the  other 
cases  putrefaction  will  be  the  third. 

That  I may  more  fully  explain  my  ideas  upon  this  subject,  it  will 
be  necessary  to  state  some  propositions. 

First;  that  so  long  as  the  animal. retains  the  susceptibility  of  im- 
pression, though  deprived  of  the  action  of  life,  it  will,  most  probablyq 
retain  the  power  of  action  when  impressed;  therefore  the  ac.tion 
may  frequently  be  suspended,  and  j-et  recoverable  ; but  when  the 
susceptibility'  of  impression  is  destroyed,  the  action  ceases  to  be  re- 
coverable. Secondly;  it  is  necessary  to  mention,  that  I consider 
part  of  the  living  principle  as  inherent  in  the  blood.f  Thirdly' ; that 
the  stomach  sympathizes  with  every  part  of  an  animal,  and  that 

* I should  consider  the  situation'  of  a person  drowned  to  be  similar  to  that  of  a 
person  in  a trance.  In  both  the  action  of  life  is  suspended  without  the  power 
being  destroyed  ; but  I am  inclined  to  believe  that  a greater  proportion  of  persons 
recover  from  trances  than  from  drowning,  because  a trance  is  the  natural  effect'of 
a disposition  in  the  person  to  liave  the  action  of  life  suspended  for  a time;  but 
drowning  being  produced  by  violence,  the  suspension  will  more  frequently  last 
for  ever,  unless  the  power  of  life  is  roused  to  action  by  some  applications  of  art. 

f That  the  living  principle  is-  inherent  in  the  blood  is  a doctrine  which  the 
nature  of  this  account  will  not  allow  me  to  discuss  ; thus  much,  however,  it  may 
be  proper  to  say,  that  it  is  founded  on  the  result  of  many  observations  and  expe- 
riments. But  it  may  be  thought  necessary  I should  here  give  a definition  of 
■what  I call  the  living  principle ; so  far,  then,  as  I have  used  the  term,  I mean  to 
express  that  principle  which  preserves  the  bcdy  from  dissolution  with  or  without 
action,  and  is  the  cause  of  all  its  actions. 


1S8 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


every  part  sympathizes  with  the  stomach  ; therefore,  whatever  acts 
upon  the  stomach  as  a cordial,  or  rouses  its  natural  and  healthy 
actions,  and  whatever  afiects  it  so  as  to  produce  debility,  has  an 
immediate  efiect  upon  every  part  of  the  body.  The  last  proposition 
I have  to  make  .is',  that  every  part  of  the  body  sympathizes  with  the 
mind;  for  whatever  afiects  the  mind,  the  body  is  affected  in  pro- 
portion. These  sympathies  are  strongest  with  the  vital  parts;  but 
besides  these  universal  sympathies  between  the  stomach,  the  mind, 
and  all  parts  of  the  body,  there  are  peculiar  sympathies,  of  which 
the  heart,  sympathizing  immediately  with  the  lungs,  is  an  instance. 
If  anything  is  received  into  the  lungs  which  is  a poison  to  animal 
life,  such  as  inflammable  air,  volatile  vitriolic  acid,  and  many  other 
well-known  substances,  the  motion  of  the  heart  immediately  ceases, 
even  much  sooner  than  if  the  trachea  had  been  tied;  and,  from  ex- 
periments, it  appears  that  anything  salutary  to  life,  applied  to  the 
lungs,  w'iil  restore  the  heart’s  action  after  it  has  been  at  rest  some 
time. 

I shall  divide  violent  deaths  into  three  kinds  ; first,  where  a stop 
is  put  only  to  the  action  of  life  in  the  animal,  but  without  any  irre- 
parable injury  to  a vital  part,  which  action,  if  not  restored  in  a 
certain  lime,  will  be  irrecoverably  lost.  The  length  of  that  time  is 
subject  to  considerable  variation,  depending  on  circumstances  with 
which  we  are  at  present  unacquainted.  The  second  is,  where  an 
injury  is  done  to  a vital  part,  as  by  taking  away  blood  till  the 
powmrs  of  action  are  lost ; or  by  a wound  or  pressure  being  made 
on  the  brain  or  spinal  marrow  while  life  remains  in  the  solids’suffi- 
cient  for  the  preservation  of  the  animal,  if  action  could  be  restored 
to  the  vital  parts.  The  third  is,  where  absolute  death  instantly 
lakes  place  in  every  part,  as  is  often  the  case  in  strokes  of  lightning; 
in  the  common  method  of  killing  eels,  by  throwing  them  on  some 
hard  substance,  in  such  manner  as  that  the  whole  length  of  the 
animal  shall  receive  the  shock  at  the  same  instant;  by  a blow  on 
the  stomach;  by  violent  affections  of  the  mind;  and  by  many 
diseases,  in -all  which  cases  the  muscles  remain  flexible.* 

How  far  that  maybe  strictly  considered  as  a violent  death  w-lflch 
is  caused  by  afiections  of  the  mind,  I will  not  pretend  to  say;  but 
if  it  is  to  have  a place  in  that  class,  it  must  be  ranked  with  those 
which  happen  from  lightning,  and  a blow  on  the  stomach;  and  in 
most  cases  of  persons  drowned,  1 can  easily  conceive  the  mind  to 
be  so  much  .affected  prior  to  the  immersion,  and  in  the  moment  im- 
mediately succeeding  it,  as  to  make  a material  difference  in  the 
power  of  recovery.  In  many  sudden  deaths  arising  from  violence, 
and  even  from  disease,  death  shall  take  place  so  immediately  that 
the  muscles  neither  contract,  nor  does  the  blood  coagulate. 

* On  the  other  hand,  when  an  eel  is  killed  hy  chopping  it  into  a number  of 
))icces,  the  powers  of  life  are  by  those  means  roused  into  action  ; and  as  every 
part  dies  in  that  active  state,  every  part  is  found  stiff  after  death.  This  explains 
the  custom  of  cutting  fish  into  pieces  while  yet  alive,  in  order  to  make  them  hard, 
usually  know'n  by  the  name  of  crimping. 


OF  PERSONS  APPARENTLY  DROWNED. 


189 


The  present  consideration  is,  under  which  of  the  kinds  of  violent 
death  drowning  can  be  classed  or  arranged  ? I am  of  opinion  it 
will  most  commonly  come  under  the  first,  and  upon  that  ground  I 
shall  principally  consider  the  subject,  always  supposing  the  body  to 
remain  flaccid. 

The  loss  of  motion  in  drowning  seems  to  arise  from  the  loss  of 
respiration,  and  the  immediate  eflects  which  that  has  upon  the  other 
vital  motions  of  the  animal ; except  what  may  have  arisen  from  the 
affections  of  the  mind.  The  privation  of  breathing  appears,  how- 
ever, to  be  the  first  cause,  and  the  heart’s  motion  ceasing,  to  be  the 
second  or  consequent ; therefore  most  probably  the  restoration  of 
breathing  is  all  that  is  necessary  to  restore  the  heart’s  motion ; for 
if  sufficient  life  still  exists  to  produce  that  effect,  we  may  suppose 
every  part  equally  ready  to  tnoVe  the  very  instant  in  which  the 
action  of  the  heart  takes  place,  their  actions  depending  so  much 
upon  it.  What  makes  it  very  probable,  that  in  recovering  persons 
drowned,  the  principal  effect  depends  upon  air  being  thrown  into 
the  lungs,  is  what  happens  at  the  birth  of  children,  when  too  much 
time  has  intervened  between  the  interruption  of  that  life  which  is 
peculiar  to  the  foetus  and  that  which  depends  on  breathing ; they 
then  lose  altogether  the  disposition  for  this  new  life ; and  in  such 
cases,  there  being  a total  suspension  of  the  actions  of  life,  the  child 
remains  to  all  appearance  dead,  and  would  certainly  die  if  air  W'ere 
not  thrown  into  its  lungs,  and  by  such  means  the  first  principle  of 
action  restored.  To  put  this  in  a still  clearer  light,  I will  give  the 
result  of  some  experiments  which  I made  in  the  year  1755  upon  a 
dog. 

A pair  of  double  bellows  were  provided,  constructed  in  such  a 
manner  as  by  one  action  to  throw  fresh  air  into  the  lungs,  and  by 
another  to  suck  out  again  the  air  which  had  been  thrown  in  by  the 
former,  without  mixing  them  together. . The  muzzle  of  these  bellow’s 
was  fixed  into  the  trachea  of  a dog,  and  by  working  them  he  wa.s 
kept  perfectly  alive.  While  this  artificial  breathing  was  going  on 
I took  ofl’  the  sternum  of  the, dog,  and  exposed  the  lungs  and  heart; 
the  heart  continued  to  act  as  before,  only  the  frequency  of  its  action 
was  considerably  increased.  When  I stopped  the  motion  of  the 
bellows  the  heart  became  gradually  weaker,  and  less  frequent  in 
its  contractions,  till  it  entirely  ceased  to  move.  By  renewing  the 
action  of  the  bellows  the  heart  again  began  to  move,  at  first  very 
faintly,  and  with  long  intermissions  ; b.ut  by  continuing  the  artificial 
breathing,  its  motion  became  as  frequent  and  as  strong  as  at  first. 
This  process  I repeated  upon  the  same  dog  ten  times,  sometimes 
stopping  for  five,  eight,  or  ten  minutes,  and  observed  that  every 
time  I left  oft’  working  the  bellows  the  heart  became  extremely 
turgid  with  blood,  the. blood  in  the  left  side  becoming  as  dark  as 
that  in  the  right,  which  was  not  the  case  when  the  bellows  were 
working.  These  situations  of  the  animal  appeared  to  me  exactly 
similar  to  drowning. 

Death  in  persons  drowned  has  been  accounted  for  by  supposing 


190 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


that  the  blood,  rendered  unfit  for  the  purposes  of  life  by  being  de- 
prived of  the  action  of  the  air  in  respiration,  is  sent  in  a vitiated 
state  to  the  brain  and  other  vital  parts,  by  which  means  the  nerves 
lose  their  eflect  upon  the  heart,  and  the  heart  in  consequence  its 
motion-  This,  however,  I am  fully  convinced  is  false ; first,  from 
the  experiments  on  the  dog,  in  which  a large  column  of  blood  so 
vitiated  (consisting  of  wliat  had  been  propelled  from  the  heart  after 
respiration  stopped,  and  might  be  supposed  the  cause  of  the  heart 
ceasing  to  act,  together  with  all  that  remained  in  the  heart  and 
pulmonary  veins),  w’as  again  pushed  forward  without  any  ill  effect 
having  been  produced  ; and  next,  from  the  return  to  life  of  persons 
drowned  and  children  still-born,  which,  were  such  a supposition 
true,  could  never  happen,  unless  we  imagine  a change  of  the  blood 
to  take  place  in  the  brain,  prior  to  the  restoration  of  the  heart’s 
motion.  This  restoration  must  therefore'  depend  immediately  on 
the  application  of  air  to  the  lungs,  and  not  on  the  effects  which  air 
has  upon  the  blood,  or  that  blood  upon  the  vital  parts. 

If  the  affections  of  the  mind  have  had  any  share  in  the  cessation 
of  action  in  the  heart.  Us  motion  wall  not  be  so  easily  restored  as 
in  other  cases.  In  our  attempts  to  recover  those  who  have  been 
drowned,  it  might  therefore  be  proper  to  inquire  if  there  had  been 
time  sufficient  for  the  person  to  form  any  idea  of  his  situation 
previous  to  his  being  pUinged  into  the  w'ater,  as  it  is  not  unlikely 
that  the  agitated  state  of  mind  might  assist  in  killing  him ; and  in 
such  case  I should  very  much  doubt  the  probability  of  restoring 
him  to  life.  In  the  history  of  those  who  have  and  who  have  not 
been  recovered,  could  the  difference  be  ascribed  to  any  such  cause, 
it  might  lead  to  something  useful ; as  in  those  who  have  had  an 
intention  to  destroy  themselves,  a great  difference  in  the  chance  of 
recovery  may  arise,  from  the  mind  having  been  previously  very 
much  affected. 

It  frequently  happens,  in  the  case  of  drowming,  that  assistance 
cannot  be  procured  till  a considerable  time  after' the  accident; 
every  moment  of  this  delay  renders  recovery  more  precarious,  the 
chances  of  which  are  not  only  diminished  in  the  pai’ts  where  the 
first  powers  of  action  principally  reside,  but  also  in  every  other 
part  of  the  body. 

In  offering  my  sentiments  on  the  method  of  treating  persons 
who  are  apparently  drowned,  I shall  say,  first,  what  I would  re- 
commend to  have  done;  secondly,  what  I would  wish  might  be 
avoided. 

'When  assistance  is  called  in  soon  after  the  immersion,  perhaps 
blowing  air  into  the  lungs  may  be  sufficient  to  effect  a recovery;* 
but  if  a considerable  time,  as  an  hour,  has  been  lost,  it  will  seldom 
be  sufficient,  the  heart  in  all  probability  having  by  that  time  lost  its 

* Perhaps  the  dephlogisticated  air  described  by  Dr.  Priestly  (oxygen  gas) 
may  prove  more  efficacious  than  common  air.  It  is  easily  procured,  and  may  be 
preserved  in  bottles  or  bladders  for  that  purpose. 


OF  PERSONS  APPARENTLY  DROWNED. 


191 


intimate  connexion  with  the  lungs.  It  will  in  these  cases,  there- 
fore, be  proper  to  apply,  mixed  with  the  air,  such  stimulating  medi- 
cines as  the  vapour  of  volatile  alkali,  which  may  easily  be  done,  by 
holding  spirits  of  hartshorn  in  a cup  under  the  receiver  of  the  bel- 
lows. I would  advise  the  air  and  volatile  alkali  to  be  thrown  in  by 
the  nose  rather  than  the  mouth,  as  the  last  mode  of  administering, 
by  pi'oducing  sickness,  is  more  likely  to  depress  than  rouse  the  living 
principle.  It  will  be  still  better  if  it  can  be  done  by  both  nostrils, 
as  applications  of  this  kind  to  the  olfactory  nerves  certainly  rouse 
the  living  principle  and  put  the  muscles  of  respiration  into  action, 
and  therefore  are  the  triore  likely  to  excite  the  action  of  the  heart: 
besides,  that  affections  of  these  nerves  are  known  to  act  more  im- 
mediately on  the  living  principle;  since  while  a strong  smell  of 
Very  sweet  flowers,  as  orange -flowers,  will  in  many  cause  fainting', 
the  application  of  vinegar  will  as  immediately  restore  the  powers 
to  action  again.  All  perfumes  in  which  thez'e  is  some  acid  rather 
rouse  than  depress,  as  the  sweet-brier,  essence  of  lemon,  &c.  If, 
during  the  operation  of  the  bellows,  the  larynx  be  gently  pressed 
against  the  oesophagus  and  spine,  it  will  prevent  the  stomach  and  in- 
testines being  too  much  distended  by  the  air,  and  leave  room  for  the 
application  of  more  effectual  stimuli  to  those  parts.  Tliis  pressure, 
however,  must  be  conducted  with  judgment  and  caution,  so  that 
the  trachea  and  the  aperture  into  the  larynx  may  both  bo  left  per- 
fectly free.  While  this  business  is  going  on  an  assistant  should 
prepare  bedclothes,  carefully  brought  to  the  proper  degree  of  heat. 
I consider  heat  as  congenial  with  the  living  principle ; increasing 
the  necessity  of  action,  it  increases  action  ; cold,  on  the  other  hand, 
lessens  the  necessity,'  and  of  course  the  action  is  diminished  : to  a 
due  proportion  of  heat,  therefore,  the  living  principle  owes  its 
vigour;  and,  from  observations  and  experiments,  it  appeal's  to  be  a 
law  of  Nature  in  animal  bodies,  that  the  degree  of  external  heat 
should  bear  a proportion  to  the  quantity  of  life;  when  it  is  w'eak- 
ened,  this  proportion  requires  great  accuracy  in  the  adjustment, 
while  greater  powers  of  life  allow  a greater  latitude.* 

I was  led  to  make  these  observations  bs  attending  to  persons 
who  are  frost-bitten,  the  effect  of  cold  in  such  eases  being  that  of 
lessening  the  living  principle.  The  powers  of  action  remain  as 
perfect  as  ever,  but  weakened,  and  heat  is  the  only  thing  wanting 
to  put  these  powers  into  action  : yet  that  heat  must  at  first  be  gradu- 
ally applied,  and  proportioned  to  the  quantity  of  the  living  principle, 
which  increasing,  the  degree  of  heat  may  likewise  be  increased.  If 
this  method  -is  not  observed,  and  too  great  a degree  of  heat  is  at 
first  applied,  the  person  or  part  loses  entirely  the  living  principle, 
and  mortification  ensues.  Such  a process  invariably  takes  place 

* It  is  upon  these  principles  that  cold  air  is  found  of  so  much  service  to  people 
who  are  reduced  by  disease,  as  the  confluent  small-pox  and  fevers,  by  diminish- 
ing heat  in  proportion  to  the  diminution  of  life,  or  lessening  the  necessity  of  the 
body’s  producing  its  own  cold. 


192 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


with  regard  to  men,  and  the  same  thing,  I am  convinced,  happens 
to  other  animals.  For  if  an  eel  is  exposed  to  a degree  of  cold  suffi- 
ciently intense  to  benumb  it  till  the  remains  of  life  are  sc'arcely  per- 
ceptible, and  still  retained  in  a cold  of  about  40°,  this  small  pro- 
portion of  living  principle  will  continue  for  a considerable  time 
without  diminution  or  increase  ; but  if  the  animal  is  afterwards 
placed  in  ’a  heat  about  60°,  after  showing  strong  signs  of  returning 
life,  it  will  die  in  a few  minutes.  INlor  is  this  circumstance  peculiar 
to  the  diminution  of  life  by  cold.  The  same  phenomena  take  place 
in  animals  which  have  been  very  much  reduced  by  hunger. 

If  a lizard  or  snake,  when  it  goes  to  its  autumnal  hiding-place, 
is  not  sufficiently  fat,  the  living  powers  are,  before  the  season  per- 
mits it  to  come  out,  ve’ry  considerably  weakened  ; perhaps  so  much 
as  not  to  admit  of  the  animal  being  again  restored.  If  animals  in 
a torpid  state  are  exposed  .to  the  sun’s  rays,  or  placed  in  any  situa- 
tion which  by  its  warmth  would  give  vigour  to, those  of  the  safne 
kind  possessed  of  a larger  shaje  of  life,  they  will  immediately  show 
signs  of  increased  life,  but  quickly  sink  under  the  experiment  and 
die  ; while  others,  reduced  to  the  same  degree  of  weakness,  as  far 
as  appearances  can  discover,  will  live  for  many  weeks,  if  kept  in 
a degree  of  cold  proportioned  to  the  quantity  of  life  they  possess. 

I observed,  many  years  ago,  in  some  of  the  colder  parts  of  this 
island,  that  when  intense  cold  had  forced  blackbirds  or  thrushes  to 
take  shelter  in  outhouses,  such  of  them  as  had  been  caught,  and 
were,  from  an  ill-judged  compassion,  exposed  to  a considerable 
degree  of  warmth,  died  very  soon.  The  reason  of  this  I did  not 
then  understand;  but  I am  now  satisfied  that  it  was  owing,  as  in 
other  instances,  to  the  degree  of  heat  being  increased  too  suddenly 
for  the  proportion  of  life  remaining  in  the  animal. 

From  these  facts  it  appears  that  warmth  causes  a greater  exertion 
of  the  living  powers  than  cold  ; and  that  an  animal  in  a weakly 
state  may  be  obliged  by  it  to  exert  a quantity-  of  the  action  of  life 
sufficient  to  destroy  the  very  powers  themselves.'*  The  same 
effects  probably  take  place  even  in  perfect  health;  it-  appearing, 
from  experiments  made  in  a heated  room,  that  a person  in  health, 
exposed  to  a great  degree  of  heat,  found  the  actions  of  life  accele- 
rated so  much  as  to  produce  at  last  faintness  and  debility.f  • 

If  bedclothes  are  put  over  the  drowned  person,  so  as  scarcely  to 
touch  him,  steam  of  volatile  alkali,  or  of  warm  balsams  and  essen- 
tial oils,  may  be  so  conveyed  as  to  come  in  contact  with  many 
parts  of  his  body;  and  it  will  certainly  prove  advantageous  if  the 
same  kind  of  stfeams  can  be  conveyed  into  the  stomach,  as  that 
seat  of  universal  sympathy  will  be  roused  by  such  means.  This 
may  be  done  by  a hollow  bougie  and  a syringe;  but  the  operation 
should  be  performed  with  all  possible  expedition,  because  the 
instrument,  by  continuing  in  the  mouth,  may  produce  sickness,  an 

*■  It  is  upon  this  principle  that  parts  mortify  in  consequence  of  inflammation. 

I Vide  Phil.  Trans,  for  the  year  1775,  vol.  Ixv.,  p.  111. 


OF  PERSONS  APPARENTLY  DROWNED. 


193 


effect  I should  choose  to  avoid,  unless  it  is  intended  to  produce  the 
action  of  vomitins:.  Some  of  the  stimulatinsf  substances,  which 
are  of  a warm  nature  and  have  an  immediate  effect,  as  spirits  of 
hartshorn,  peppermint-water,  jliice  of  horse-radish,  and  many 
others  which  produce  a more  lasting  stimulus  in  a fluid  state,  and 
are  found  to  quicken  the  pulse  of  a man  in  health,  as  balsams  and 
turpentines,  may  be  thrown  into  the  stomach ; but  the  quantity 
must  be  small,  as  they  have  a tendency  to  produce  sickness;  for  it 
may  be  imagined  that  what  would  produce  debility,  or  lessen  action 
when  in  health,  would  in  opposite  circumstances  prevent  actions 
from  taking  place.  The  application  of  steams  and  other  substances 
should  also  be  thrown  up  by  the  anus ; and  the  process  recom- 
mended under  the  first  head  of  treatment  should  still  be  continued 
while  that  recommended  under  the  second  is  putting  in  practice, 
the  last  being  only  an  auxiliary  to  the  first.  The  first,  in  many 
cases,  may  succeed  alone;  but  the  second  without  the  first  must,  I 
think,  always  fail  where  the  pow'ers  of  life  are  considerably 
weakened.  Motion  may  possibly  be  of  service,  it  may  at  least  be 
tried;  but,  as  it  has  less  effect  than  any  other  of  the  usually  pre- 
scribed stimuli,  it  should  be  the  last  applied.*  I would  recommend 
to  the  operator  the  same  care  in  regulating  the  application  of  every 
one  of  these  methods  as  I did  before  in  that  of  heat,  as  each  may 
have  the  same  property  of  entirely  destroying  the  feeble  action 
which  they  have  excited,  if  administered  in  too  great  a proportion. 
Instead,  therefore,  of  increasing  and  hastening  the  operations  on 
the  first  signs  of  returning  life  being  observed,  as  is  usually  done,  I 
should,  wish  them  to  be  applied  more  gently  and  gradually,  that 
their  increase  afterwards  may  be  directed,  as  nearly  as  possible,  in 
a degree  proportioned  to  the  powers  as  they  arise.  As  the  heart  is 
commonly  the  last  part  that  ceases  to  act,  it  is  probably  the  first 
part  that  takes  on  the  action  of  recovery.  When  it  begins  to  move, 

I would  advise  lessening  the  application  of  air  to  the  lungs,  and 
enjoin  those  employed  to  observe  with  great  attention  when  the 
muscles  of  respiration  begin  to  act,  that  our  endeavours  may  not 
interfere  with  their  natural  exertions,  yet  that  we  may  be  still  ready 
to  assist.  I would  by  all  means  discourage  bloodletting,  which  I 
think  weakens  the  animal  principle  and  life  itself,  consequently 
lessens  both  the  powers  and  dispositions 'to  action ; and  I would 
advise  being  careful  not  to  call  forth  any  disposition  that  might 
depress,  by  introducing  things  into  the  stomach  which  ordinarily 
create  nausea  ; as  that  also  will  have  a similar  effect,  except  it  can 
be  carried  so  far  as  to  excite  the  action  of  vomiting,  by  which  the 
stomach  could  relieve  itself.  It  will  be  prudent  likewise  to  avoid 

* Electricity  has  been  known  to  be  of  service,  and  should  be  tried  when  other 
methods  have  failed.  It  is  probably  the  only  method  we  have  of  immediately 
stimulating' the  heart;  all  other  methods  being  more  by  sympathy.  I have  not 
mentioned  injecting  stimulating  substances  directly  into  the  veins,  though  it 
might  be  supposed  a proper  expedient,  because,  in  looking  over  my  experiments 
on  that  subject,  I found  none  where  animal  life  received  increase  by  that  method. 

18 


194 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


administering  by  the  anus  anything  that  may  be  likely  to  produce 
an  evacuation  that  way,  every  such  evacuation  tending  to  lessen 
the  animal  powers.  I have  purposely  avoided  speaking  of  the 
fumes  of  tobacco,  which  always  produce  sickness  or  purging, 
according  as  they  are  applied. 

Whoever  is  appointed  for  the  purpose  of  recovering  drowned 
persons  should  have  an  assistant  well  acquainted  with  the  methods 
intended  to  be  made  use  of ; that  while  the  one  is  going  on  with 
the  first  and  most  simple  methods,  the  other  maybe  preparing  what 
else  may  be  proper,  so  that  no  time  may  be  lost  between  the  opera- 
tions ; and  this  is  the  more  necessary,  as  the  first  means  recom- 
mended will,  in  all  cases,  assist  the  second  ; and  both  together  may 
often  be  attended  with  success,  though  each  separately  might  have 
failed. 

A proper  apparatus  is  also  essentially  necessary  to  the  institu- 
tion : a description  of  which  I here  annex.  First,  a pair  of  bellows, 
so  contrived,  with  two  separate  cavities,  that  by  expanding  them, 
when  applied  to  the  nostrils  or  mouth  of  a patient,  one  cavity  may 
be  filled  with  the  common  air,  and  the  other  with  air  sucked  out 
from  the  lungs  ; and  by  shutting  them  again,  the  common  air  may 
be  thrown  into  the  lungs,  and  that  which  is  sucked  out  of  the  lungs 
be  discharged  into  the  room.  The  pipe  of  these  should  be  flexible, 
in  length  a foot  or  a foot  and  a half,  and  at  least  three  eighths  of 
an  inch  in  width:  as  the  artificial  breathing  may  be  continued  by 
such  means,  while  the  other  operations,  except  the  application  of 
the  stimuli  to  the  stomach,  are  going  on  ; which  cannot  conveniently 
be  done  if  the  nozzle  of  the  bellows  be  introduced  into  the  nose. 
The  end  next  the  nose  should  be  double,  and  applied  to  both  nos- 
trils. Secondly,  a syringe,  with  a hollow  bougie,  or  flexible  catheter, 
of  sufficient  length  to  go  into  the  stomach,  and  convey  any  stimu- 
lating matter  into  it,  without  affecting  the  lungs.  Thirdly,  a small 
pair  of  bellows,  such  as  are  commonly  used  in  throwing  fumes  of 
tobacco  up  the  anus,  by  which  stimulating  fluids  or  even  fumes 
may- be  thrown  in. 

I shall  conclude  this  account  by  proposing  that  all  who  are  em- 
ployed in  this  practice  be  particularly  required  to  keep  an  accurate 
journal  of  the  means  used,  and  the  degree  of  success  attending 
them;  whence  we  may  be  furnished  with  facts  sufficient  to  enable 
us  to  draw  conclusions,  on  which  a certain  practice  may  hereafter 
be  established. 


17.  AN  ACCOUNT  OF  CERTAIN  RECEPTACLES  OF  AIR 
IN  BIRDS,  WHICH  COMMUNICATE  WITH  THE 
LUNGS  AND  EUSTACHIAN  TUBE. 

SixcE  the  account  of  these  receptacles  was  read  before  the  Royal 
Society,  in  the  year  1774,  I have,  by  the  dissection  of  a number  of 
birds,  been  able  to  make  some  additional  observations  relative  to 


OF  AIR-CELLS  IN  BIRDS. 


195 


the  extent  of  the  air-cells  which  communicate  with  the  lungs  in 
animals  of  this  class.  These  latter  observations  were  not,  however, 
made  in  consequence  of  any  regular  design  to  investigate  this  sub- 
ject further,  as  to  have  established  the  principle  seemed  all  that  was 
necessary;  unless  by  general  observations  we  could  hope  to  throw 
more  light  on  the  final  intention  of  this  remarkable  piece  of 
mechanism. 

Before  the  period  I have  mentioned,  the  communication  subsist- 
ing in  birds,  between  the  air-cells  of  the  lungs  and  other  cavities 
of  the  body,  had  not  been  clearly  explained,  nor  even  much  attended 
to  by  anatomists  or  natural  historians.*  It  is  a singularity  of 
structure  peculiar  to  this  tribe  of  animals;  and  on  account  of  it 
cannot,  I imagine,  be  unacceptable  to  the  public. 

It  is  not  my  present  intention  to  enter  into  minute  descriptions  of 
all  the  particular  communications  of  this  sort  discoverable  in  birds 
by  dissection,  but  only  to  mention  such  general  facts  as  may  serve 
to  introduce  the  subject  into  natural  history,  and  lead  to  an  inquiry 
into  the  purposes  which  this  structure  was  intended  to  answer. 
With  this  view  I shall  endeavour  to  give  some  idea  of  the  con- 
struction of  the  lungs,  and  of  the  air-receptacles  in  birds,  occasion- 
ally remarking  the  circumstances  in  which  these  principally  differ 
from  what  is  seen  in  other  animals. 

The  mechanism  of  the  lungs  in  birds,  which  renders  them  fit  for 

* [The  continuation  of  the  air-passages  of  the  lungs  into  large  membranous 
receptacles,  situated  in  the  abdominal  cavity,  was  first  discovered  and  described 
by  Harvey  (On  Generation,  8vo.,  1663,  p.  7 ; Opera  Omnia,  4to.,  1766,  p.  185). 
The  abdominal  air-cells  of  the  ostrich  are  figured  in  Perault’s  Collection  of  Ana- 
tomical Memoirs  of  the  French  Academicians.  Borelli,  in  explaining  the  causes 
of  the  greater  specific  levity  of  birds,  observes,  “Hoc  patet,  quia  ossa  avium 
fistulosa,  valde  excavata  et  subtilia  sunt,  ad  instar  radicum  pennarum  scapulae, 
costae  et  brachia  parum  carnosa  sunt;  pectus  et  abdomen  amplas  cavitates  aere 
plenas  habent;  pennae  tamen  et  plumte  levissimae  sunt.”  {Be  Motu  Animalium, 
4to.,  1685,  p.  231,  prop.  194.)  Borelli  appears,  however,  to  have  believed  both 
the  quills  of  the  feathers  and  the  hollow  bones  to  have  contained  only  a light 
marrow.  The  discovery  that  the  bones  of  birds  contained  air  was  first  published 
in  the  year  1774,, — in  England  in  the  Philosophical  Transactions  of  that  year, 
which  contained  Mr.  Hunter’s  ‘ Account,’  &e.,  read  before  the  Royal  Society, 
February  27,  3 774  ; and  in  Holland  in  the  Verhandeling  van  Bataafsche  Genoot- 
schte,  Rotterdam,  1774,  in  which  Camper’s  discovery  of  the  same  structure  was 
first  published.  Camper  transmitted,  in  the  year  1773,  an  account  of  his  re- 
searches on  the  air-bones  of  birds  to  the  French  Academy,  which  was  published 
in  the  Memoires  de  Mathemaliques  et  Physique,  4to.,  in  1776,  Whilst,  therefore, 
we  may  be  willing  to  admit  that  Camper’s  Memoir  was  founded  on  an  indepen- 
dent discovery,  we  must  also  conclude  that  the  mass  of  valuable  observations  on 
the  air-receptacles  of  birds,  communicated  to  the  Royal  Society  some  months 
before  the  first  publication  of  Camper’s  discovery  in  the  Dutch  language,  was 
equally  original.  The  French  translator  of  Carus’s  Comparative  Anatomy,  in 
a prefatory  sketch  of  the  History  of  the  Science,  introduces  John  Hunter  to  the 
reader’s  notice  as  follows:  “Le  premier,  il  (Camper)  a fait  remarquer  que  les 

os  longs  du  squelette  de.s  Oiseaux  sont  creuses  de  cavites  dans  lesquelles  Pair 
a la  facilite  de  s’introduire,  parce  qu’elles  communiquent  avec  I’organe  pulmo- 
naire,  decouverte  que  Hunter  eut  Pimpndeur  de  s’approprier  quelques  annees 
apres.”  (Jourdan’s  Cams,  tom.  i.,  p.  xxxi.)  Truly  the  ignorance  of  such  an 
assertion  can  only  be  equalled  by  its  impudence.)  ; 


196 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


conveying  air  to  different  parts  of  the  body,  consists  principally  in 
certain  communications. 

It  has  been  asserted  that  birds  have  no  diaphragm  ; but  this 
opinion  must  have  arisen  either  from  a want  of  observation,  or 
from  too  confined  an  idea  of  a diaphragm  ; for  there  is  a moderately 
strong,  but  thin  and  transparent  niembrane,  covering  the  lower 
surface  of  the  lungs,  and  adhering  to  them,  that  affords  insertion  to 
several  thin  muscles  which  arise  from  the  inner  surfaces  of  the  ribs. 
The  use  of  this  part  seems  to  be  that  of  lessening  the  concavity  of 
the  lungs  towards  the  abdomen  at  the  time  of  inspiration,  and 
thereby  assisting  to  dilate  the  air-cells,  for  which  reason  it  is  to  be 
considered  as  answering  one  main  purpose- of  a diaphragm.  Be- 
sides this  attachment  of  the  lungs  to  the  diaphragm,  they  are  also 
connected  to  the  ribs,  and  to  the  sides  of  the  vertebrce.*^ 

Such  adhesions  are  peculiar  to  this  tribe  of  animals,  and  are  of 
singular  use,  nay,  in  fact  are  absolutely  necessary  in  lungs  like  those 
of  birds,  out  of  which  it  is  intended  the  air  should  find  a passage 
into  other  cavities.  For  if  the  lungs  were  loose  in  the  cavity  of 
the  thorax,  as  is  the  case  in  many  other  animals,  the  cells  of  the 
lungs  could  not  be  expanded,  either  by  the  depression  of  the  dia- 
phragm, or  the  elevation  of  the  ribs;  since  the  air  rushing  in  to  fill 
up  the  vacuum  produced  in  the  cavity  of  the  chest  by  these  actions 
would  take  the  straight  road  from  the  trachea  through  the  passages, 
and  of  consequence  would  expand  no  part  of  the  lungs  which  lay 
out  of  that  line,  whereby  respiration  would  be  totally  prevented, 
and  an  efiect  produced  exactly  similar  to  what  happens  in  other 
animals  when  the  lungs  are  so  much  wounded  as  to  allow  a free 
exit  to  the  air  in  that  part.f 

The  cells  in  the  bodies  of  birds  which  receive  air  from  the  lungs 
are  to  he  found  both  in  the  soft  parts  and  in  the  bones,  and  have  no 
communication  with  the  cavity  of  the  common  cellular  membrane. 
Some  of  these  air-bags  are  placed  in  the  larger  cavities,  as  in  the 
abdomen;  and  others  are  so  lodged  in  the  interstices  of  muscles, 
blood-vessels,  and  nerves,  about  the.  breast,  axilla,  &c.,  as  at  first  to 
give  the  appearance  of  the  common  connecting  membrane.  Some 
communicate  immediately  with  one  another,  and  all  may  be  said 
to  have  a communication  by  means  of  the  lungs.  They  are  of  very 
different  sizes,  as  may  best  suit  the  particular  circumstances  of  the 
parts  in  which  they  are  placed. 

The  bones  which  receive  air  are  of  two  kinds ; some,  as  the 
sternum,  ribs,  and  vertebrae,  having  their  internal  substance  divided 
into  innumerable  cells ; whilst  others,  as  the  os  humeri  and  o's  femoris, 
are  hollowed  out  into  one  large  canal,  with  sometimes  a few  bony 
columns  running  across  at  its  extremities.  Bones  of  this  kind  may 
be  distinguished  from  those  that  do  not  receive  air  by  several  marks : 
first,  by  their  less  specific  gravity;  secondly,  by  being  less  vascular 
than  the  others,  and  therefore  whiter;  thirdly,  by  their  containing 


[See  Harvey,  on  Generation,  p.  6.] 


t [Ibid.,  p.  7.] 


OF  AIR-CELLS  IN  BIRDS. 


197 


little  or  no  oil,  and  consequently  being  more  easily  cleaned,  and 
when  cleaned,  appearing  much  whiter  than  common  bones;  fourthly, 
by  having  no  marrow,  or  even  any  bloody  pulpy  substance  in  their 
cells  ; fifthly,  by  not  being  in  general  so  hard  and  firm  as  other 
bones  ;*  and  sixthly,  by  the  passage  that  allows  the  air  to  enter  the 
bones,  which  can  be  easily  perceived.  In  the  recent  bone  we  may 
readily  discover  holes  or  openings  not  filled  with  any  soft  substance, 
as  blood-vessels  or  nerves ; several  of  these  holes  are  placed  together, 
near  that  end  of  the  bone  which  is  next  to  the  trunk  of  the  bird,  and 
are  distinguishable  by  having  their  external  edges  rounded  off,  which 
is  not  the  case  with  the  holes  through  which  either  nerves  or  blood- 
vessels pass  into  the  substance  of  the  bone.  When  birds  break  any 
of  the  bones  which  contain  air,  the  surrounding  parts  often  become 
emphysematous. 

There  are  openings  in  the  lungs  by  which  air  is  transmitted  to  the 
other  parts ; and  the  membrane  or  diaphragm  above-mentioned  is 
perforated  in  several  places  with  holes  of  a considerable  size,  which 
admit  of  a free  communication  between  the  cells  of  the  lungs  and 
the  abdomen,  a circumstance  which  has  been  frequently  noticed. 
To  each  of  these  perforations  is  joined  a distinct  membranous  bag, 
extremely  thin  and  transparent,  which  bags  being  afterwmrds  con- 
tinued through  the  whole  of  the  abdomen,  and  attached  to  the  back 
and  sides  of  that  cavity,  are  kept  firm  in  their  proper  situations, 
each  receiving  the  air  from  their  respective  openings.  There  is  no 
occasion  to  describe  here  all  the  bags,  or  their  attachments,-  it 
being  sufficient  to  have  said  that  they  extend  over  the  whole 
abdomen. 

The  lungs  at  the  anterior  part,  contiguous  to  the  sternum,  have 
openings  into  certain  membranous  cells  which  lie  upon  the  sides  of 
the  pericardium,  and  communicate  with  the  cells  of  the  sternum. 
At  the  superior  part  the  lungs  have  a communication  with  the  large 
cells  of  a loose  network,  thi’ough  which  the  trachea,  oesophagus, 
and  great  vessels  pass  as  they  are  going  to  and  from  the  heart. 
When  these  cells  are  distended  with  air,  the  size  of  that  part  where 
they  lie  is  very  considerably  increased,  and  this  enlargement  is  in 
general  a mark  of  either  the  passion  of  anger  or  love.  It  is  plainly 
seen  in  the  turkey-cock,  the  pouting-pigeon,  &c.,  and  is  very  visible 
in  the  breast  of  a goose  when  she  cackles.  These  cells  communi- 
cate with  others  in  the  axilla,  under  the  large  pectoral  muscle,  and 
in  some  birds  are  still  further  extended.  In  the  pelican,  for  instance, 
the  skin  of  the  whole  body,  even  to  the  tip  of  the  wing,  is  united  to 
the  part  underneath  by  means  of  these  cells,  which  are  equally 
formed ; and  when  the  skin  is  removed,  the  two  separated  surfaces 
appear  as  if  honeycombed.  When  the  cells  are  distended  the  skin 
is  removed  to  a considerable  distance,  by  which  means  the  volume 

* The  bones  of  some  birds  are  so  soft  that  they  can  be  squeezed  together 
with  the  finger  and  thumb ; the  bones  of  the  extremities,  however,  have  very 
solid  sides. 


18* 


198 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


is  proportionally  increased.*  In  most  birds,  I believe  in  all  that  fly, 
these  axillary  cells  communicate  with  the  cavity  of  the  os  humeri, 
by  means  of  small  openings  in  the  hollow  surface  near  the  head  of 
that  bone;  in  some  they  are  continued  down  the  w'ing,  communi- 
cating with  the  ulna  and  radius  ; in  others  tliey  reach  even  as  far 
as  the  pinions.  The  ostrich,  however,  is  an  exception. 

The  posterior  edge  of  the  lungs  (which  lies  on  the  sides  of  the 
spine,  and  projects  backwards  between  the  ribs,)  communicates 
with  the  cells  of  the  bodies  of  the  vertebrae,  with  those  of  the  ribs, 
the  canal  of  the  medulla  spinalis,  and  the  cells  of  the  sacrum  and 
other  bones  of  the  pelvis  ; from  M’hich  parts  the  air  finds  a passage 
into  the  cavity  of  the  thigh-bone.  This  takes  place  in  the  greatest 
number  of  birds;  but  in  some  the  air  is  even  continued  part  of  the 
way  down  the  thighs.  This  account  agrees  with  what  we  gene- 
rally find,  though  some  birds  have  more,  and  some  fewer  of  these 
communications ; for,  in  the  ostrich,  no  air  gets  into  the  os  humeri, 
yet  it  enters  into  every  other  part,  as  before  described,  and  in  very 
large  quantities.  In  the  common  fowl  no  air  appears  to  enter  any 
bone  except  the  os  humeri.  The  woodcock  has  no  air-cells,  either 
in  the  first  bones  of  the  winsr  or  in  the  thigh-bones.  On  the  other 
hand,  in  the  pelican  the  air  passes  on  to  the  ulna  and  radius,  and 
into  those  bones  which  answer  to  the  carpus  and  metacarpus  of 
quadriipeds.t 

Thus  the  cells  of  the  abdomen,  those  surrounding  the  pericardium, 
those  situated  at  the  lower  and  fore  part  of  the  neck  and  in  the 
axilla,  those  in  the  cellular  membrane  under  the  pectoral  muscles, 
as  well  as  in  that  which  unites  the  skin  to  the  body,  all  communi- 
cate with  the  kyigs,  and  are  capable  of  being  filled  with  air;  and 
again,  from  them  the  cells  of  the  sternum,  ribs,  vertebrae  of  the 
back  and  loins,  bones  of  the  pelvis,  the  humeri,  the  ulna  and  radius, 
with  the  pinions  and  thigh-bones,  can  in  many  birds  be  furnished 
with  air. 

It  is  not  by  the'lungs  alone  that  air  is  conveyed  into  the  bones  of 
birds,  for  the  cells  of  the  diploe  between  the  two  plates  of  the  skull, 
in  some  birds,  I’eceive  a considerable  quantity  of  air  by  the  Eusta- 

* [While  inflating  the  air-cells  of  a gigantic  crane  (^Ciconia  Jlrgala),  in  which 
bird  they  are  continued  along  the  wing,  beneath  the  skin,  as  in  the  pelican,  the 
wings  became  extended  as  the  air-cells  were  filled.  This  phenomenon  suggested 
to  me  a secondary  use  of  the  air-cells,  which  appears  not  to  have  been  noticed, 
viz.,  to  render  mechanical  assistance  to  the  muscles  of  the  wings,  both  by  keep- 
ing the  wing  extended  during  the  long  hovering  flight  peculiar  to  this  bird,  and 
also  by  compressing  and  bracing  the  muscles,  as  is  done  by  the  fasciae  of  the  ex- 
tremities in  man.] 

f [In  the  hornbill  the  air  is  also  extended  into  the  phalanges  of  the  toes,  and  in 
short  into  every  bone  in  the  skeleton;  whilst  in  the  penguin,  on  the  other  hand, 
the  air-cells  are  confined,  as  in  reptiles,  to  the  thoracic  abdominal  cavity,  and  not 
a single  bone  of  the  skeleton  is  permeated  by  the  atmospheric  fluid.  These  birds 
present  the  two  extremes  of  the  condition  of  the  respiratory  apparatus  described 
by  Hunter  in  the  present  paper.] 


OF  AIR-CELLS  IN  BIRDS. 


199 


chian  tube.*  Of  this  the  owl  is  a remarkable  instance.  The  lower 
jaw  of  some  kinds  is  likewise  supplied  with  air,  and  often  by  the 
same  canal.f  Some  authors  have  considered  the  diploe  in  the 
cranium  of  a bird  as  a continuation  of  the  mammillary  process,  and 
looked  upon  it  as  a circumstance  peculiar  to  singing  birds,  which  is 
not  really  true. 

These  facts,  which  had  been  formerly  observed,  led  me  in  the 
year  1758  to  make  several  experiments  upon  the  breathing  of  birds, 
that  might  prove  the  free  communication  between  the  lungs  and  the 
before-mentioned  parts. 

First,  I made  an  opening  into  the  belly  of  a cock,  and  having  in- 
troduced a silver  canula,  tied  up  the  trachea.  I found  that  the 
animal  breathed  by  this  opening,  and  might  have  lived;  but  by  an 
inflammation  in  the  bowels  coming  on,  adhesions  were  produced, 
and  the  comm.unication  was  cut  off". 

I next  cut  the  wing  through  the  os  humeri,  in  another  fowl,  and 
tying  up  the  trachea,  as  in  the  cock,  found  that  the  air  passed  to 
and  from  the  lungs  by  the  canal  in  this  bone.  The  same  experi- 
ment was  made  with  the  os  femoris  of  a young  haw'k,  and  was  at- 
tended with  a similar  result.  But  the  nassasre  of  air  through  the 
divided  parts,  in  both  these  experiments,  especially  in  the  last,  was 
attended  with  more  difficulty  than  in  the  former  one  ; it  was  indeed 
so  great  as  to  render  it  impossible  for  the  animal  to  live  longer  than 
evidently  to  prove  that  it  breathed  through  the  cut  bone. 

I have  made  several  preparations  of  these  cells,  by  throwing  into 
the  trachea  an  injection,  commonly  called  the  corroding  injection, 

* The  only  thing  in  other  animals  similar  to  this  communication  in  birds,  of  the 
cells  of  bones  with  the  external  air,  is  that  which  takes  place  in  the  internal  ear 
of  quadrupeds,  by  means  of  the  Eustachian  tube. a 

j When  I wrote  this  account  to  send  it  to  the  Royal  Society,  I did  not  then 
know  by  what  means  this  was  done;  for  in  that  I said,  “but  by  what  means  I 
do  not  know;”  that  is,  I did  not  know  whether  it  was  conveyed  by  the  trachea, 
where  it  passes  along  tlie  neck,  or  the  Eustachian  tube.  Professor  Camper, 
when  he  did  me  the  honour  to  call  upon  me,  was  so  obliging  as  to  take  some 
pains  to  show  me,  in  the  lower  jaw  of  the  hawk,  the  hole  where  the  air  entered, 
which  makes  me  suspect  he  did  not  understand  what  I had  written.  For  after 
having  given  the  marks  by  which  such  openings  were  particularly  distinguished, 
it  w’ill  hardly  be  supposed  I could  say  that  I did  not  know  the  hole  where  the 
air  entered. 


a [Camper,  besides  citing  the  mastoid  processes  as  an  analogous  structure  in 
the  mammalia,  also  adduces  the  extensive  sinuses  containing  air  in  the  cranium  of 
the  elephant.  The  air-cavities  of  the  diploe  of  the  cranial  bones  in  the  porcupine 
are  also  remarkable  for  their  extent.] 

1)  [In  this  note  we  have  undesigned  evidence  that  Flunter  had  never  read  the 
Memoir  of  Camper,  or  he  would  hardly  have  omitted  to  notice  the  error  into 
w'hich  the  Dutch  anatomist  falls  with  reference  to  the  source  whence  the  bones 
of  the  head  derive  their  internal  supply  of  air.  Camper  states  that  it  is  received 
by  the  meatus  aurfitow,  believing  that  birds  had  no  Eustachian  tubes:  “Pair 
entre  dans  le  diploe  du crane  entier  par  les  trous  auditifs ; car  les  oiseaux  n’ont  point 
de  trompes  d’Eustache  comme  les  quadtupedes  et  les  amphibies.”  {Mem.  de- 
Matliem.  et  de  Physique,  tom.  vii.  1776,  p.  334.)] 


200 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


which  first  filled  the  air-cells  of  the  lungs,  then  all  the  others,  such 
as  the  cells  in  the  abdomen,  anterior  and  superior  part  of  the  chest, 
axilla,  os  humeri,  cells  of  the  back-bone  and  thigh  ; and  the  whole 
being  afterwards  put  into  spirit  of  sea-salt,  and  corroded,  the  cast 
of  injection  came  out  entire. 

The  singularity  of  these  communications  in  birds  put  me  upon 
considering  what  might  be  their  final  intention.  At  first  I supposed 
it  might  be  intended  to  assist  the  act  of  dying,  that  being  the  cir- 
cumstance which  appears  the  most  peculiar  to  birds;  and  it  might 
be  of  service  in  that  respect,  I thought,  by  increasing  the  volume 
and  strength  with  the  same  quantity  of  matter,  wthout  adding  to 
the  weight  of  the  whole,  which  indeed  would  rather  be  diminished 
by  the  dilference  of  specific  gravity  between  the  external  and  in- 
ternal air.  This  opinion  was  strengthened  by  discovering  that  the 
feathers  of  birds  contained  also  a considerable  quantity  of  air,  in 
the  very  part  which  requires  the  greatest  strength,  and  by  the 
analogy  which  is  observed  between  this  mechanism  in  birds  and 
what  is  discoverable  in  most  kinds  of  fishes  ; for  these  last  have  air 
contained  within  their  bodies,  which  I believe  is  commonly  supposed 
to  lessen  their  specific  gravit\q  although  this  does  not  appear  so  ne- 
cessary in  fishes,  which  move  in  a much  heavier  element  than  birds.* 

* When  we  consider  tliat  the  elevating  and  suspending  apparatus  is  much 
smaller  in  fishes  than  in  birds,  we  may  reasonably  conceive  the  air  in  them  was 
intended  as  a kind  of  equilibrium  between  tbe  fish  and  water;  and  that  progres- 
sive motion  was  the  only  thing  wanted  in  the  actions  of  fishes.  Were  we  to 
reason  upon  general  principles  alone,  we  should  suppose  that  those  fishes  who 
have  the  largest  air-bags  should  liave  their  muscles  of  a greater  specific  gravity, 
and  those  fishes  that  have  none  should  have  the  lightest  flesh  ; therefore  that  the 
flesh  of  the  salmon  and  cod,  w'hich  have  an  air-bag,  should  be  heavier  than  that 
of  the  shark,  which  has  none.  But  to  know  how  far  this,  which  appeared  to  be 
reasonable,  was  a fact,  I made  the  following  experiments: 

Experiment  I.  1 took  a portion  of  muscle  of  the  shark,  cod,  and  salmon,  of  the 
same  weight  in  air;  and  first  examined  how  far  they  occupied  the  same  space, 
by  immersing  them  in  water,  and  observing  the  rise  or  fall  of  the  water  upon  each 
of  them  being  separately  immersed  in  it. 

The  shark  occupied  the  smallest  space,  the  salmon  a little  more,  and  the  cod 
the  largest. 

Experiment  II.  I then  suspended  the  same  three  portions,  upon  a level,  in  a 
glass  vessel  filled  with  water  about  two  feet  high,  and  let  them  all  go  at  the  same 
instant;  to  see  which  would  fall  through  the  water  in  the  shortest  space  of  time. 
The  shark  got  to  the  bottom  first,  the  salmon  next,  and  the  cod  last. 

It  is  necessary  to  observe  that,  in  both  these  experiments,  the  difference  in  hulk 
and  in  the  times  of  their  falling  was  very  little,  but,  however,  sufficient  to  ascertain 
the  fact  for  which  the  experiments  were  instituted. 

To  see  how  far  the  muscular  flesh  of  birds  was  specifically  lighter  than  that  of 
a quadruped,  I repeated  the  above  experiments  upon  a portion  of  a hind,  of  a 
pigeon,  and  of  a sheep  ; but  could  discover  no  visible  difference  in  their  weight. 

It  may  be  observed  there  are  in  common  two  situations  of  oil  in  fishes:  in  one 
it  is  diffused  through  the  fish,  as  if  the  body  had  been  steeped  in  it,  as  in  the 
salmon,  herring,  &c.  In  the  other  it  is  found  in  the  liver,  as  in  all  of  the  ray 
kind,  cod,  &c.,  and  in  general  those  that  have  it  in  one  part  have  none  in  the 
other;  however,  there  are  some,  although  I believe  but  few,  who  have  their  oil 
in  form  of  what  may  be  called  fat,  viz.,  in  flakes  in  the  interstice  of  parts,  as  the 
sturgeon.  The  liver,  in  those  of  the  ray  kind,  is  large,  and  extended  through 


OF  AIR-CELLS  IN  BIRDS. 


201 


But  when  I found  that  the  ostrich  (which  is  not  intended  to  fly)  was 
amply  provided  with  these  cells;  and  that  the  common  fowl,  and 
many  others  of  that  class,  which  are  endowed  with  the  faculty  of 
flying,  were  less  liberally  supplied  ; when  I saw  that  even  the  wood- 
cock, which  flies  and  is  supposed  to  be  a bird  of  passage,  was  inferior 
in  this  respect  to  the  ostrich,  and  that  the  bat  differed  not  in  structure 
from  animals  that  do  not  fly  ;*  I was  compelled,  by  so  many  con- 
tradictions to  theory,  to  suppose  that  this  singular  mechanism  might 
be  intended  for  some  other  purpose. 

The  next  conjecture  that  offered  was  that  these  cells  were  to  be 
considered  as  an  appendage  to  the  lungs;  and  to  this  I was  led  by 
the  analogy  observable  between  birds  and  amphibious  animals. 
For  although  both  in  the  bird  and  amphibious  tribe,  as  the  snake, 
viper,  and  many  others,  the  lungs  are  continued  down  through  the 
whole  belly,  in  form  of  two  bags,f  and  therefore  appear  to  be  larger 
than  the  lungs  in  any  other  animal,  yet  in  all  of  them  the  quantity 
of  surface  exposed  to  the  air  is  much  less  than  in  the  quadruped  ; 
for  the  cells  of  the  lungs  in  the  bird  are  larger, and  in  the  snake,  &c. 
the  upper  part  only  can  perform  the  office  of  respiration  with  any 
degree  of  effect,  the  lower  having  comparatively  but  few  air-ves- 
sels. The  air  must  pass  through  this  upper  part  before  it  gets  to 
the  lower  in  inspiration,  and  must  also  repass  in  expiration,  so  that 
the  respiratory  surface  has  more  air  applied  to  it  than  what  the  lungs 
of  themselves  could  contain.  It  is  not  however  to  be  supposed  that 
the  air  can  be  made  to  pass  to  and  fro  in  bones  as  in  parts  which 
admit  of  contraction  and  dilatation;  the  purpose  answered  by  these 
bony  cells  must  therefore  be  different,  and  perhaps  they  should  be 
considered  as  reservoirs  of  air.J  There  is  in  fact  a great  similarity 

the  belly ; therefore  it  might  be  supposed  to  lighten  the  body,  from  oil  being 
lighter  than  water  or  the  flesh  ; but  we  have  oil  in  the  liver  of  the  cod,  and  in  the 
salmon  and  herring  the  nil  is  diffused  through  the  whole’:  therefore  I am  afraid 
we  are  not  yet  acquainted  with  the  full  effect  of  the  air-bladder  in  fishes. 

* [This  is  not  absolutely  true  ; for  it  is  a remarkable  fact, — and  one  which 
gives  additional  probability  to  the  hypothesis  of  Borelli  as  to  the  final  intention 
of  the  air-cells  of  birds  in  diminishing  the  specific  gravity  for  the  facilitation  of 
flight, — that  in  one  genus  of  bats  (^Ni/cteris  of  modern  naturalists)  “remarkable  for 
their  lofty  and  continued  flight,  air-cells  are  continued  beneath  the  integument, 
which  are  inflated  from  the  cheek-pouches.  “The  skin  adheres  to  the  body,” 
says  Bell,  in  his  excellent  article  Cheiroptera  (Cyclop,  of  Anatomy,  p.  599), 
“ only  at  certain  points,  where  it  is  connected  b_v  means  of  a loose  cellular  mem- 
brane : it  is  therefore  susceptible  of  being  raised  from  the  surface,  on  the  back 
as  well  as  on  the  under  parts.  These  large  spaces  are  filled  with  air  at  the  will 
of  the  animal,  by  means  of  large  cheek-pouches,  which  are  pierced  at  the  bottom, 
and  thus  communicate  with  the  subcutaneous  spaces  just  mentioned.  When 
the  animal,  therefore,  wishes  to  inflate  its  skin,  it  inspires,  closes  the  nostrils, 
and  then,  contracting  the  cavity  of  the  chest,  the  air  is  forced  through  the  open- 
ings in  the  cheek-pouches  under  the  skin,  whence  it  is  prevented  from  returning 
by  means  of  a true  sphincter,  with  which  those  operxings  are  furnished,  and  by 
large  valves  on  the  neck  and  back.  By  this  curious  mechanism  the  bat  has  the 
power  of  so  completely  blowing  up  the  spaces  under  the  skin  as  to  give  the  ioea 
of  a little  balloon,  furnished  with  wings,  a head,  and  feet.”] 

t [In  most  snakes  the  abdominal  air-bag  is  single,  but  a rudiment  of  the 
second  lung  exists.] 

^ It  is  not  to  be  supposed  that  the  air  in  the  cells  in  birds  will  be  changed 


202 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


between  birds  and  that  class  of  animals  called  amphibia;  and 
although  a bird  and  a snake  are  not  the  same  in  the  construction 
of  the  respiratory  organs,  yet  the  circumstance  of  the  air  passing  in 
both  beyond  the  lungs,  into  the  cavity  of  the  abdomen,  naturally 
leads  us  to  suppose  that  a structure  so  similar  is  designed  in  each  to 
answer  a similar  purpose.  This  analogy  is  still  further  supported 
by  the  lungs  in  both  consisting  of  large-cells.*  Now  in  amphibious 
animals  the  use  of  such  a conformation  of  the  lungs  is  evident,  as 
it  is  in  consequence  of  this  structure  that  they  require  to  breathe 
less  frequently  than  others  ; and  in  this  respect  it  may  in  birds  have 
some  connexion  with  flying,  as  that  motion  might  easily  be  imagined 
to  render  frequency  of  respiration  inconvenient,  and  a reservoir  of 
air  would  therefore  become  singularly  useful.  Although  we  are  not 
to  consider  this  structure  in  birds  to  be  an  extension  of  lungs,  yet 
I can  easily  conceive  this  accumulation  of  air  to  be  of  great  use 
in  respiration.  For  it  was  observed  before  respecting  the  amphibia, 
that  the  air  in  its  passage  to  from  these  cells  must  certainly  have  a 
considerable  effect  upon  the  blood  in  the  lungs,  by  allowing  a much 
greater  quantity  of  air  to  pass  in  a given  time  than  if  there  was  no 
such  construction  of  parts  ;f  and  this  opinion  will  not  appear  to  be 
ill  founded,  if  we  consider  that  both  in  the  bird  and  in  the  viper 
the  surface  of  the  lungs  is  small  in  comparison  to  what  it  is  in 
many  otlier  animals  which  have  not  this  extension  of  cavity.  It  is 
also  a corroborating  circumstance,  that  in  the  fowl,  the  air  might  have 
passed  by  a much  readier  way  than  through  the  lungs  into  all  the 
cells  about  the  breast,  neck,  axilla,  wings,  &c.,  as  these  could  have 
been  filled  from  the  low'er  end  of  the  trachea,  upon  which  many  of 

while  flying ; only  accumulated  and  retained;  not  in  the  least  influenced  by 
either  inspiration  or  expiration.  It  might  be  asked,  Where  is  th6  stricture  upon 
the  air  when  flying,  so  as  to  keep  the  parts  distended  1 Is  it  upon  the  outlets 
from  the  lungs,  or  is  it  at  the  glottis,  as  in  the  quadruped  I For  we  may  observe 
that  when  an  animal  is  using  considerable  exercise,  it  never  either- expands  the 
lungs,  nor  makes  a full  expiration,  giving  the  ribs  and  diaphragm  as  little  extent 
of  motion  as  possible,  so  that  the  body  may  be  kept  firm,  which  obliges  it  to 
breathe  oftener;  and  as  this  quantity  of  air  is  not  sufficient  for  the  accelerated 
motion  of  the  blood,  the  animal  gets  what  is  called  out  of  breath,  which  is  no 
more  than  the  two  not  being  proportioned  ; and  when  it  rests,  it  breathes  as  quick 
and  takes  as  lotig  strokes  as  possible,  to  make  up  the  loss.  So  that  in  exercise 
we  probably  breathe  less  air. 

* [The  air-cells  are  smaller,  and  much  more  numerous  in  the  lungs  of  birds 
than  in  the  corresponding  anterior  or  true  respiratory  portion  of  the  lungs  of  rep- 
tiles. The  analogy  which  Hunter  here  mentions,  as  also  that  between  the  ab- 
dominal air-receptacles  of  birds  and  the  air-bladders  of  fishes,  to  which  he  previ- 
ously alludes,  had  not  escaped  the  observation  of  Ilervey,  who  says,  “ Quin  etiam 
(quod  tamen  a nemine  hactenus  observatum  mernini)  avium  bronchia,  sive  asperae 
arteria5  fines,  in  abdomen  perforantur,  aeremque  inspiratum  intra  cavitates  illarum 
membranarum  recondunt.  Qnemadmodum  pisces,  et  serpentes  intra  amplas 
vesicas  in  abdomine  positas  eundem  altrahunt  et  reservant;  eoque  facilius  natare 
existimantur.” — De  Generatione  Jlnimalium,  Ex.  HI.] 

f It  may,  perhaps,  occur  to  some,  that  the  whole  of  these  communicating  cells 
are  to  be  considered  as  extended  lungs  ; but  I can  hardly  think  that  any  air  which 
gets  beyond  the  vesiculated  lungs  themselves  is  capable  of  affecting  the  blood  of 
the  animal,  as  the  other  cavities  into  which  it  enters,  whether  of  the  soft  parts  or 
of  the  bones,  appear  to  be  very  little  vascular. 


OF  AIR-CELLS  IN  BIRDS. 


203 


them  lie.  But  the  air  must  now  take  a roundabout  passage  both  in 
its  way  in  and  its  way  out,  those  openings  being  upon  the  exterior 
surface  of  the  lungs.  We  must  not,  however,  give  up  the  idea  of 
such  structure  being  of  use  in  flying  ; for  I believe  we  may  set  it 
down  as  a general  rule,  that  in  the  birds  of  longest  and  highest  flight, 
as  eagles,  this  diffusion  of  air  is  extended  further  than  in  the  others. 
This  opinion  is  strengthened  by  comparing  the  structure  above 
described  with  the  respiratory  organs  in  the  flying  insects,  which 
are  composed  of  cells  diffused  through  the  whole  body ; these  are 
extended  even  into  the  head  and  down  the  extremities ; while  there 
is  no  such  appearance  in  the  insects  that  do  not  fly,  as  the  spider; 
but  wliy  the  pelican  should  be  so  amply  provided  I cannot  say,  not 
knowing  the  natural  history  of  that  bird  sufficiently  to  be  able  to 
judge  of  this  point.  Do  they  carry  weights  in  the  large  fauces  so 
great  as  to  require  such  an  increase  of  substance  without  increase 
of  weight? 

How  far  this  construction  of  the  respiratory  organs  may  assist 
birds  in  singing  deserves  investigation,  as  the  vast  continuance  of 
song,  between  the  breathings,  in  a canary-bird  would  appear  to 
arise  from  it.  This  is  a subject,  however,  which  I shall  not  at 
present  enter  upon.* 

* [The  objection  offered  by  Hunter  in  the  preceding  note  to  the  use  of  the  air- 
cells  as  accessory  organs  of  respiration,  is  weakened,  if  not  removed,  by  the 
anatomical  fact  that  the  bronchiee  open  into  them  by  such  direct  and  wide 
apertures  as  to  render  it  most  probable  that  much  of  the  air  passes  at  once  into 
the  air-receptacles  without  having  previously  been'decomposed  in  the  vesicles  of  the 
lungs.  It  may  be  concluded,  therefore,  that  the  respiratory  function  is  heightened, 
in  harmony  with  the  increased  energies  of  the  circulating  and  locomotive  powers 
in  birds,  by  means  of  the  extensive  system  of  continuous  air-receptacles  above 
described,  which  operate  both  by  effecting  a change  in  the  blood  of  the  pulmonary 
circulation  in  the  return  of  the  air  of  the  cells  through  the  bronchial  tubes,  and 
also  by  the  change  which  the  blood  undergoes  in  the  capillaries  of  the  systemic 
circulation,  which  are  in  contact  with  the  air-receptacles. 

A second  use  of  the  air-receptacles  in  reference  to  the  respiratory  function 
arises  out  of  the  mechanical  aid  which  they  afford  in  the  action  of  breathing. 
During  inspiration  the  sternum  of  the  bird  is  depressed  or  recedes  from  the 
spine,  the  angle  between  the  vertebral  and  sternal  ribs  is  made  less  acute,  and 
the  thoracic  cavity  proportionally  enlarged  ; the  air  then  rushes  into  the  lungs 
and  into  the  thoracic  air-receptacles,  while  those  of  the  abdomen  become  flaccid ; 
when  the  sternum  is  raised,  or  approximated  towards  the  spine,  part  of  the  air  is 
expelled  from  the  lungs  and  thoracic  cells  by  the  trachea,  and  part  driven,  into 
the  thoracic  receptacles,  which  are  thus  alternately  enlarged  and  diminished 
with  those  of  the  thorax.  Hence  the  lungs,  notwithstanding  their  fixed  con- 
dition, are  subject  to  due  compression  through  the  medium  of  the  contiguous  air- 
receptacles,  and  are  affected  equally  and  regularly  by  every  motion  of  the  ster- 
num and  ribs. 

A third  use,  and  one  which  Hunter  inclines  to  admit,  is  that  of  rendering  the 
whole  body  specifically  lighter,  in  relation  to  the  peculiar  actions  of  flight.  A 
diminution  of  specific  gravity  must  necessarily  follow  the  desiccation  of  the 
marrow  and  other  fluids  in  those  spaces  which  are  occupied  with  the  air-cells, 
and  by  the  rarefaction  of  the  contained  air  by  the  heat  of  the  body.  In  harmony 
with  this  view  are  the  facts,  not  only  that  the  quantity  of  air  admitted  into  the 
system  is  in  proportion  to  the  general  powers  of  flight,  but  also  that  in  birds  where 
the  skeleton  is  only  partially  permeated  by  air,  this  is  especially  distributed  to 


204 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


18.  A DESCRIPTION  OF  THE  NERVES  WHICH  SUPPLY 
THE  ORGAN  OF  SMELLING. 

The  nerves  being  in  themselves  perhaps  the  most  difficult  parts 
of  an  animal  body  to  dissect,  becomes  a reason  why  we  are  still 
unacquainted  with  many  of  their  minuter  ramifications ; yet  if  a 
knowledge  of  these,-  together  with  that  of  their  origin,  union,  and 
reunion,  is  at  all  connected  with  their  physiology,  the  more  accu- 
rately they  are  investigated  the  more  perfectly  will  the  functions 
of  the  nerves  be  understood. 

I have  no  doubt,  if  their  physiology  was  sufficiently  known,  that 
we  should  find  the  distribution  and  complica;tion  of  nerves  so  imme- 
diately connected  with  their  particular  uses,  as  readily  to  explain 
many  of  those  peculiarities  for  which  it  is  now  so  difficult  to 
account.  What  naturally  leads  to  this  opinion  is,  the  origins  and 
number  of  nerves  being  constantly  the  same,  and  particular  nerves 
being  invariably  destined  for  particular  parts,  of  which  the  fourth 
and  sixth  pair  of  nerves  are  remarkable  instances.  We  may  there- 
fore reasonably  conclude,  that  to  every  part  is  allotted  its  particu- 
lar branch,  and  that  however  complicated  the  distribution  may  be, 
the  complication  is  always  regular. 

There  are  some  nerves  which  have  a peculiarity  in  their  course, 
as  the  recurrent  and  chorda  tympani;  and  others  which  are  appro- 
priated to  particular  sensations,  as  those  which  go  to  four  of  the 
organs  of  sense,  seeing,  hearing,  smelling,  and  tasting  ; and  some 
parts  of  the  body  having  peculiar  sensations  (as  the  stomach  and 
penis),  we  may,  without  impropriety,  include  the  fifth,  or  sense  of 
feeling.  This  general  unifonrtity  in  course,  connexion,  and  distri- 
bution, will  lead  us  to  suppose  that  there  may  be  some  other  pur- 
pose to  be  answered  than  mere  mechanical  convenience ; and 
many  of  the  variations  which  have  been  described  in  the  dissec- 
tions of  nerves,  1 believe  to  have  arisen  from  the  blunders  of  the 
anatomist,  rather  than  from  any  irregularity  in  their  number,  mode 
of  ramifying,  course,  distribution,  or  connexion*  with  each  other. 

those  members  which  are  most  employed  in  locomotion  : thus  it  is  admitted  into 
the  w'ing-bones  of  the  owl,  but  not  into  the  femur;  while  in  the  ostrich  the  air 
penetrates  to  the  femur,  but  not  the  humerus  or  other  bones  of  the  wing. 

I have  already  alluded  to  the  secondary  use  which  the  air-cells  may  afford  to 
some  large  and  long-winged  bird,  which,  like  the  Argala,  or  the  Frigate  Bird, 
hover  with  a sailing  motion  for  a long-continued  period  in  the  upper  regions  of  the 
air,  by  diminishing  the  necessity  for  muscular  exertion  by  the  tendency  of  the 
distended  air-cells  to  maintain  the  wings  outstretched.  Of  the  same  adventitious 
character  is  the  use  finally  suggested  Iry  Hunter  to  the  air-receptacles,  of  contri- 
buting to  sustain  the  song  of  birds,  and  to  impart  to  it  tone  and  strength.  It  is 
no  just  objection  to  this  function  that  the  air-cells  exist  in  birds  wliich  are  not 
endowed  with  the  mechanism  and  power  of  song,  since  it  is  not  pretended  that 
this  is  the  primary  or  exclusive  office  of  the  air-cells.  The  latest  writer  on  the 
pneumaticity  of  birds,  M.  Jacquemin,  has  indeed  reproduced  this  suggestion  of 
Hunter’s  as  a novel  idea.] 

* Here  it  is  to  be  understood  I do  not  mean  lateral  connexion,  such  as  two 
branches  uniting  into  one  chord  and  then  dividing;  or  a branch  going  to  a part. 


THE  NERVES  OF  THE  ORGAN  OF  SMELLING. 


205 


We  observe  no  such  uniformity  in  vessels  carrying  fluids,  but 
find  particular  purposes  answered  by  varying  their  origin  and  dis- 
tribution: the  pulmonary  artery  answers  a very  different  purpose 
in  the  circulation  of  the  blood  from  that  of  the  aorta  ; yet  both  arise 
from  the  same  source,  the  heart.  The  course  of  the  arteries  is  such 
as  will  convey  the  blood  most  conveniently,  and  thei’efore  not 
necessarily  uniform,  it  not  being  very  material  by  what  channel, 
provided  the  blood  is  conveyed  to  the  part;  though  in  particular 
instances  certain  purposes  may  be  answered  by  a peculiarity  in 
origin  and  distribution,  as  happens  in  the  testicle  of  quadrupeds. 
This  observation  respecting  arteries  is  likewise  applicable  to  veins, 
and  still  more  to  the  absorbent  vessels ; in  which  last,  regularity 
is  even  less  essential  than  in  the  veins. 

Whoever,  therefore,  discovers  a new  artery,  vein,  or  lymphatic, 
adds  little  to  the  stock  of  physiological  knowledge;  but  he  who 
discovers  a new  nerve,  or  furnishes  a more  accurate  description  of 
the  distribution  of  those  already  known,  affords  us  information  in 
those  points  which  are  most  likely  to  lead  to  an  accurate  knowledge 
of  the  nervous  system ; for  if  we  consider  how  various  are  the 
origins  of  the  nerves,  although  all  arise  from  the  brain,  and  how 
different  the  circumstances  attending  them,  we  must  suppose  a 
variety  of  uses  to  arise  out  of  every  peculiarity  of  structure.^ 

Indeed,  if  we  reflect  on  the  actions  arising  immediately  from  the 
will  and  affections  of  the  mind,  we  must  see  that  the  origin,  con- 
nexion, and  distribution  of  the  nerves  ought  to  be  exact,  as  there 

either  single  or  double,  for  still  it  is  the  same  nerve ; or  whether  a branch  unites 
with  another  alittl'e  sooner  or  a little  later,  for  slill  it  is  the  same  branch.  Such 
effects  may  arise  more  from  a variety  in  the  shape  of  the  bodies  they  belong  to, 
than  any  variety  in  the  nerves  themselves. a 

* [With  reference  to  anatomical  researches  on  the  nervous  system.  Sir  Charles 
Bell  has  observed : “ Whilst  the  nerves  are  supposed  to  proceed  from  one  great- 
centre,  to  have  the  same  structure  and  functions,  and  to  be  all  sensible,  and  all 
of  them  to  carry  what  has  been  vaguely  called  nervous  power,  these  discoveries 
of  new  nerves  and  ganglia  are  worse  than  useless;  they  increase  the  difficulty, 
and  repel  inquiry.” — Exposition  of  the  Natural  System  of  the  Nerves  of  the  Human 
Body,  1824,  p.  70. 

The  different  views  entertained  by  Hunter  on  this  subject  doubtless  arose  from 
his  belief  that  a variety  of  uses  arose  out  of  the  various  'origins  and  other  pecu- 
liarities of  structure  of  the  nerves.  Hence  he  was  led  to  trace  the  different  nerves 
which  are  distributed  to  a single  organ  to  their  different  origins,  and  to  infer  that 
ihe'organ  thereby  received  different  sensitive  endowments.  It  is  this  principle, 
in  a more  extended  application  from  the  nerves  to  their  component  filaments,  so 
far  as  they  have  different  origins,  which  forms  the  basis  of  the  present  improved 
doctrine  of  the  nervous  system.  “ The  key  to  the  natural  system  of  the  nerves,” 
says  Bell,  “ will  be  found  in  the  simple  proposition,  that  each  filament  or  track 
of  nervous  matter  has  its  peculiar  endowment,  independently  of  the  others  which 
are  bound  up  along  with  it,  and  that  it  continues  to  have  the  same  endowment 
throughout  its  whole-length.” — Ibid.l 


a [See  the  observations  of  Swan  on  the  exceptions,  which  occur  in  the  uniformity 
of  the  anatomical  conditions  of  the  nervous  system,  in  his  excellent  ‘ Demonstra- 
tion of  the  Nerves  of  the  Human  Body,’  pp.  29,  30,  31.] 

19 


306 


HUNTER  ON  THE  ANIMAL  OECONOMY. 


are  parts  whose  actions  immediately  depend  upon  such  circum- 
stances. The  brain  may  be  considered  as  having  an  intelligence 
with  the  body  ; but  no  such  intercourse  subsists  between  the  differ- 
ent parts  of  the  body  and  the  heart. 

- In  the  summer  of  1754,  being  much  employed  in  dissecting  the 
nerves  passing  out  of  the  skull,  1 was,  of  course,  led  to  trace  many 
of  their  connexions  with  those  from  the  medulla  spinalis  ; and  was 
assisted  by  Dr.  Smith,  then  pursuing  his  studies  in  London.*  The 
better  to  trace  these  serves  through  the  foramina  of  the  skull,  I 
steeped  the  head  in  a weakened  acid  of  sea-salt  till  the  bones  were 
rendered  soft,  and  that  the  parts  might  be  as  firm  as  possible,  and 
at  the  same  time  free  from  any  tendency  to  putrefaction  (it  being 
summer),  the  acid  was  not  diluted  with  water,  but  with  spirit. 
When  the  bones  were  rendered  soft,  pursuing  my  intention,  I dis- 
sected the  first  pair  of  nerves,  and  discovered  their  distribution  ; and 
having  made  a preparation  of  the  parts  in  which  they  were  found, 
I immediately  had  drawings  made  from  them,  with  a view  to  have 
presented  the  account  to  the  Royal  Society  ; but  other  pursuits  pre- 
vented it.-)-  Engravings  were  afterwards  made  from  these  drawings, 
and  the  preparation  was  repeatedly  shown  by  Drt  Hunter,  in  his 
courses  of  anatomy,  who,  at  the  same  time,  pointed  out  that  altera- 
tion in  the  mode  of  reasoning  upon  those  nerves  which  would 
naturally  arise  from  this  discovery.  In  this  dissection  I found 
several  nerves,  principally  from  the  fifth  pair,  going  to  and  lost  upon 
the  membrane  of  the  nose ; but  suppose  that  those  have  nothing  to 
do  with  the  sense  of  smelling,  it  being  more  than  probable  that  what 
may  be  called  organs  of  sense  have  particular  nerves,  whose  mode 
of  action  is  different  from  that  of  nerves  producing  common  sensa- 
tion, and  also  different  from  one  another,  and  that  the  nerves  on 
which  the  peculiar  functions  of  each  of  the  organs  of  sense  depend, 
are  not  supplied  from  different  parts  of  the  brain.  The  organ  of 
sight  has  its  peculiar  nerve  ; so  has  that  of  hearing;  and  probably 
that  of  smelling  likewise;  and,  on  the  same  principle,  w'e  may  sup- 

* Dr.  Smith  was  afterwards  teacher  in  chemistry  and  anatomy  in  the  university 
of  Oxford  ; is  now  Savilian  professor  of  geoinetry,  and  lecturer  in  physiology. 
This  account  of  the  first  pair  of  nerves,  as  also  of  the  branches  of  the  fifth,  is  taken 
from  the  original  description  written  by  him,  and  taken  from  my  dissection  when 
I was  tracing  them. 

f Dr.  Scarpa,  professor  of  anatomy  at  Pavia,  while  in  London  in  1782,  ac- 
quainted me  that  he  had  dissected  the  ramifications  of  the  olfactory  nerves, 'and 
that  on  his  return  to  Italy  he  meant  to  publish  an  account  of  them.  At  this  time 
I showed  him  my  drawings  and  engravings.  I have  lately  been  informed  that 
he  has  published  his  account,  but  have  not  met  with  it:  I have,  however,  seen 
one  of  his  engravings,  which  was  executed  in  London,  and  is  very  elegant.  It 
only  shows  those  on  the  septum  narium,  whose  minuteness  is  rather  carried 
further  than  the  power  of  dissection,  and  the  ramifications  are  more  regular  than 
we  find  them  in  Nature. a 


a [See  Scarpa,  Jlnatomic.se.  Disquisiiiones  de  Auditu-et  Olfaciu,  fol.  1789,  and 
Anaiomicarum  Annotationum,  Liber  secundus  De  Organo  olfadus  praecipuo,  deque 
Nervis  nasalibus  interioribus  e Pariquinto  Nervorum  cerebri,  4to.,  1782.] 


THE  NERVES  OP  THE  ORGAN  OF  SMELLING. 


207 


pose  the  organ  of  taste  to  have  a peculiar  nerve.  Although  these 
organs  of  sense  may  likewise  have  nerves  from  different  parts  of 
the  brain,  yet  it  is  most  probable  such  nerves  are  only  for  the 
common  sensations  of  the  part,  and  other  purposes  answered  by 
nerves.  Thus  we  find  nerves  from  difterent  origins  going  to  the 
parts  composing  the  organ  of  sight,  which  are  not  at  all  concerned 
in  the  immediate’ act  of  vision;  it  is  also  probable,  although  not  so 
demonstrable,  that  the  parts  composing  the  ear  have  nerves  be- 
longing to  them  simply  as  a part  of  the  body,  and  not  as  the  organ 
of  a particular  sense  : and  if  we  carry  this  analogy  to  the  nose,  w^e 
shall  find  a nerve,  which  we  may  call  the  peculiar  nerve  of  that 
sense  : and  the  other  nerves  of  this  pai't,  derived  from  other  origins, 
only  conveying  common  sensation,  and  we  may  suppose  only  in- 
tended for  the  common  actions  of  the  part.  This  mode  of  reasoning 
is  equally  applicable  to  the  organ  of  taste ; and  if  the  opinion  of 
peculiar  nerves  going  to  particular  organs  of  sense  be  well  founded, 
then  the  reason  is  evident  why  the  nose,  as  a part  of  our  body, 
should  have  nerves  in  common  with  other  parts,  besides  its  peculiar 
nerves  ; and,  as  the  membrane  of  the  nose  is  of  considerable  extent, 
and  has  a great  deal  of  common  sensation,  we  may  suppose  the 
nerves  sent  to  this  part  for  that  purpose  will  not  be  few  in  number. 
It  is  upon  this  principle  the  fifth  pair  of  nerves  may  be  supposed  to 
supply  the  eye  and  nose  in  common  with  other  parts  ;*  and  upon 
the  same  principle,  it  is  more  than  probable,  that  every  nerve  so 
affected  as  to  communicate  sensation,  in  whatever  part  of  the  nerve 
the  impression  is  made,  always  gives  the  same  sensation  as  if 
affected  at  the  common  seat  of  the  sensation  of  that  particular 
nerve.f 

* [Since  the  period  when  Hunter  wrote  this  remarkabie  paper,  in  whjeh  the 
principle  of  different  nerves  having-  particular  functions  in  relation  to  differences 
of  origin  and  other  anatomical  conditions  is  so  distinctly  enuntiated,  the  attention 
of  physiologists  has  been  more  especially  called  to  the  fact  of  the  organs  of  sense 
being  supplied  by  nerves  from  different  sources,  for  -the  purpose  of  different  en- 
dowments, by  the  experiments  of  Magendie.  He  divided  the  fifth  pair  of  nerves 
within  the  cranium,  and  thus  contributed  to  define  more  exactly  than  had  before 
been  done  the  importance  of  common  sensation  to  the  safety  of  some  of  the  organs 
of  sense,  as  the  eye,  and  also  the  share  which  touch  bear's  in  the  impressions 
received  by  the  organs  of  special  sense,  as  in  that  of  smell. 

Physiological  science  does  not  perhaps  afford  a more  striking  example  of  fhe 
inferiority  of  mere  experimental  inquiry  to  that  which  is  based  on  extensive 
anatomical  Induction,  than  the  singular  conclusions  at  which  Magendie  arrived 
after  performing  the  experiment  above  alluded  to.  There  are  few  physiologists, 
however,  who  do  not  adopt  the  conclusions  of  Hunter,  that  the  organs  of  sense 
receive  their  endowments  of  ordinary  sensation  from  the  fifth  pair,  which  is 
common  to  each,  in  preference  to  the  well-known  view  originally  adopted  by 
Magendie.  (See  Journal  de  Pysiologie  Exper.,  vol.  iv,,  169.  “ Le  nerf  olfactif 
est-il  I’organe  de  I’odoratl”)] 

f I knew  a gentleman  who  had  the  nerves  which  go  to  the  glans  penis  comr 
pletely  destroyed  by  mortification,  almost  as  high  as  the  union  of  the  penis  with 
the  pubes;  and  at  the  edge  of  the  old  skin,  at  the  root  of  the  penis,  where  the 
nerves  terminated,  was  the  peculiar  sensation  of  the  glans  penis  ; and  the  .sensa- 
tion of  the  glans  itself  was  now  only  corfamon  sensation  ; therefore  the  glans  has 


208 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  first  pair  of  nerves  arriving  at  the  part  of  its  destination  as 
soon  as  it  escapes  from  the  skull,  and  immediately  ramifying,  has 
rendered  its  distribution  more  obscure  than  that  of  the  others, 
■whose  course  to  the  part  to  which  they  are  allotted  is  visible  and  to 
be  traced.  As ‘the  body  of  the  nerve,  while  within  the  skull’,  is  pulpy 
and  composed  of  the  brain  itself,  it  easily  breaks  off  at  the  very  di- 
vision and  exit  of  the  small  branches;  it  therefore  becomes  impos- 
sible to  trace  them,  as  we  usually  do  other  nerves ; and  they  have 
by  most  physiologists  been  considered  as  never  forming  chords,  but 
going  on  in  their  pulpy  form  to  be  distributed  on  the  membrane  of 
the  nose,  in  a mode  somewhat  similar  to  that  of  the  optic  nerve, 
and  to  what  is  commonly  supposed  to  take  place  with  respect  to 
the  portio  mollis  of  the  seventh  pair.  Winslow  has  suggested  an 
idea  that  the  first  pair  forms  chords;  but  it.is  only  as  an  assertion, 
and  not  having  described  them,  that  alone  was  not  sufficient  to  alter 
the  former  mode  of  reasoning. 

Haller,  who  is  to  be  considered  as  the  latest  anatomist  and  phy- 
siologist, who  has  published  on  the  subject,  on  whom  we  can  depend 
says,  that  “ The  first  pair  of  nerves  makes  its  way  into  the  nose 
covered  by  the  pia  mater  only,  very  little  altered  from  what  it  was 
when  within  the  cavity  of  the  skull.”*  This  shows  that  Haller  re- 
tained the  old  idea  concerning  these  nerves;  but  W'e  shall,  find  that 
they  become  firm  chords  immediately  upon  piercing  the  dura  mater 
and  cribriform  plate  of  the  ethmoid  bone. 

"^he  first  pair,  while  within  the  skull,  differs  in  some  respects 
from  all  other  nerves  : firstly,  it  seems  to  be  made  up  of  a cortical 
and  medullary  substance;  while  the  others  appear  to  consist  of  me- 
dullary alone ; and  secondly,  it  is  different,  in  that  it  does  not  seem 
to  be  composed  of  fasciculi,  and  has  but  one  covering  from  the  pia 
mater  investing  the  whole  nerve,  whereas  other  nerves  appear  to 
have  a covering  round  each  fasciculus;  and  this  is  probably  the 
reason  why  the  first  pair  is  weaker  while  within  the  skull  than  the 
others.  Its  form  is  somewhat  triangular,  having  three  edges,  from 
lying  in  a groove  made  by  two  convolutions  of  the  brain.  The 
course  is  forwards,  a little  upwards  and  inwards,  and  where  it  lies 
upon  the  cribriform  plate  of  the  ethmoid  bone  becomes  somewhat 
larger,  and  divides  into  a great  many  branches,  like  so  many  roots, 
answering  to  the  number  of  holes  in  that  plate,  except  one  left  for  a 
branch  of  the  fifth  pair;  but  these  divisions  we  cannot  see,  they 
being  covered  by  the  body  of  the  nerve,  which  cannot  be  raised 
without  breaking  off  the  small  branches  at  their  origin.  As  the 

probably,  different  nerves,  and  those  for  common  sensation  may  come  through  the 
bod}^  of  the  penis  to  the  glans. 

A Serjeant  of  marines,  tvho  had  lost  the  glans  and  the  greater  part  of  the  body 
of  the  penis,  upon  being  asked  if  he  .ever  felt  those  sensations  ■which  are  peculiar 
to  the  glans,  declared,  that  upon  rubbing  the  end  of  the  stump,  it  gave  him  exactly 
the  sensation  which  friction  upon  the  glans  produced,  and  was  followed  by  an 
emission  of  the  semen. 

Elementa  Physiologiae,  vol.  v.,  p.  151. 


OP  SOME  BRANCHES  OF  THE  FIFTH  PAIR  OF  NERVES.  209 


branches  of  the  nerve  pass  through  this  bone,  they  seem  to  take 
processes  from  the  dura  mater  along  with  them,  then  becoming  firm 
chords,  similar  to  other  nerves.  These  branches,  after  they  have 
got  through  the  bone,  form  themselves  into  two  planes  or  divisions, 
one"  passing  on  the  septum,  the  other  on  the  turbinated  bones. 
Those  of  the  septum  narium,  in  their  passage  to  the  nose,  are  first 
continued  a little  way  down,  in  bony  canals  of  tlie  perpendicular 
lamella  of  the  ethmoid  bone,  which  holes  become  small  grooves  in 
that  bone  ; and  those  on  the  opposite  side  being  more  numerous  and 
smaller,  pass  down  through  small  holes  that  are  on  the  inside  plate 
of  the  ethmoid  bone,  which  holes  are  likewise  continued  into  grooves, 
for  a little  way,  upon  that  plate.  When  the  branches  get  upon  the 
membrane  of  the  nose,  they  subdivide  into  a great  many  smaller 
ones,  which  are  somewhat  flattened,  and  are  only  to  be  seen  on  that 
side  of  the  membrane  that  adheres  to  the  bones,  not  being  visible 
at  all  on  the  other ; so  that  the  dissection  of  these  nerves  is  no  more 
than  separating  the'  membrane  and  bone  from  each  other.  They 
can  hardly  be  dissected  all  round  ; and  the  further  they  are  traced 
upon  the  membrane  the  fainter  they  become,  and  growing  smaller 
they  sink  deeper  and  deeper  into  the  mem.brane  to  get  on  its 
outer  surface,  where  we  must  suppose  they  terminate.  Those  upon 
the  septum  pass  down  a little  radiated,  and  the  branches,  especially 
at  the  upper  part,  or  at  their  first  setting  out,  unite  with  one  another. 
Those  on  the  side  next  the  antrum,  when  they  have  reached  the 
membrane  of  the  nose,  in  their  course  to  the  superior  turbinated 
bone,  form  a very  considerable  network  or  plexus ; and  when  they 
reach  that  bone,  do  not  all  go  round  its  convex  curvated  pendulous 
edge  to  the  concave  side,  but  some  passing  through  its  substance 
get  immediately  upon  it,  which  is  the  reason  why  we  find  so  many 
holes  in  that  bone.  It  is  difficult  to  trace  them  further ; but  we 
have  reason  to  suppose  that  they  go  through  the  inferior  turbinated 
bone  in  the  same  manner,  since  we  find  similar  holes. 


19.  A DESCRIPTION  OF  SOME  BRANCHES  OF  THE 
FIFTH  PAIR  OF  NERVES. 

Lv  tracing  the  course  of  the  olfactory  nerves,  I also  discovered 
several  branches  of  the  fifth  pair  not  comnionly  known,  particularly 
two  that  were  supposed  to  go  to  the  membrane. of  the  nose  for  the 
sense  of  smelling,  but  which  only  pass  through  that  organ  to  their 
place  of  destination.  The  first  is  a small  nerve  from  the  first  branch 
of  the  fifth  pair;  or,  accoi’ding  to  Winslow,  the  nervus  ophthalmi- 
cus Willisii,  which  small  nerve  is  called  by  Winslow  the  nasal. 
This  branch,  after  having  passed  out  of  the  skull  into  the  orbit,  re- 
enters the  cranium  through  the  foramen  orbitariumanterius,  and  gets 

19* 


210 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


on  the  cribriform  plate  of  the  ethmoid  bone;  from  thence  it  passes 
down  through  one  of  the  anterior  holes  of  the  cribriform  plate,  and  after 
having  continued  its  course  in  a groove  on  the  nasal  process  of  the 
frontal  bone,  runs  forward  and  downward  in  a similar  groove  on 
the.  inside  of  the  os  nasi ; from  thence  getting  on  the  outside  of  the 
cavity  of  the  nose,  it  runs  along  the  cartilaginous  part  of  the  ala, 
and  near  the  extremity  of  the  nose  mounts  up  upon  the  tip  of  the 
ala,  and  then  dipping  down  between  the  two  alse,  is  lost  on  the 
anterior  extremity  of  the  cartilaginous  septum.  In  its  course  it 
sends  several  small  filaments  into  the  alse. 

The  second  is  a branch  of  the  superior  maxillary  nerve ; for 
that  nerve,  having  passed,through  the  foramen  rotundum,  divides 
and  sends  off  several  branches,  one  of  which  passing  backwards 
and  inwards,  through  .the  foramen  commune,  between  the  orbitar 
process  of  the  palate,  and  the  root  of  the  ala  of  the  sphenoid  bone, 
gives  a branch  which  gets  into  a fissure  that  seems  to  separate  the 
root  of  the  ala  from  the  body  of  the  sphenoid  bone,  where  that  bone 
makes  the  roof  of  the  nose.  This  branch  then  passes  along  the 
under  surface  of  the  body  of  the  sphenoid  bone,  in  its  way  to  the 
septum  narium,  and  getting  upon  that  part,  passes  along  between  its 
membranes  and  the  bone  : its  course  is  downwards,  and  forwards 
towards  the  foramen  incisivum,  through  which  it  passes  and  is  lost 
in  the  gum  behind  the  first  dentes  incisores,  and  on  the  membrane 
of  the  roof  of  the  mouth  at  that  part. 

There  is  another  branch  of  the  superior  maxillary  nerve,  which 
comes  off"  from  a large  branch  that  is  going  down  to  the  mouth, 
uvula,  &c.,  and  this  branch,  with  its  division  into  two,  has  been 
described  by  Professor  Meckel,  of  Berlin ; but  after  tracing  one  of 
these  into  the  portio  dura,  he  pursued  the  search  no  further.  This 
branch  of  the  superior  maxillary  nerve  passes  back  through  the 
foramen  pterygoideum,  accompanies  the  carotid  artery  as  it  passes 
across  the  posterior  edge  of  the  foramen,  and  there  divides  into  two 
branches;  one  .of  which  passes  down  along  with  the  carotid  artery,, 
through  the  basis  of  the  skull,  and  proceeding  in  a direction  con- 
trary to  the  course  of  the  artery,‘in  contact  with  that  branch  of  the 
cervical  ganglion  that  passes  up  with  the  carotid  artery'to  join  the 
sixth  pair,  then  joins  the  first  cervical  ganglion.  The  other  bfanch 
decussates  that  artery  on  its  upper  surface,  and  getting  upon  the 
anterior  side  of  the  petrous  portion  of  the  temporal  bone,  enters  a 
small  hole  near  the  bottom  of  that  large  one  which  affords  a pas- 
sage to  the  seventh  pair  of  nerves,  joining  the  portio  dura  just  where 
that  nerve,  making  its  first  turn,  passes  along  with  it  through  what 
is  called  the  aqueduct.  This  nerve,  composed  of  portio  dura,  and 
the  branch  of  the  fifth  pair,  sends  off,  in  the  adult,  the  chorda 
tympani  before  its  exit  from  the  skull ; and  in  the  foetus  immediately 
after.  The  termination  of  the  branch,  called  chorda  tympani,  I 
shall  not  describe;  yet  I am  almost  certain  it  is  not  a branch  of  the 
seventh  pair  of  nerves,  but  the  last-descibed  branch  from  the  fifth 
pair;  for  I think  I have  been  able  to  separate  this  branch  from  the 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


211 


portio  dura,  and  have  found  it  lead  to  the  chorda  tympani ; perhaps 
it  is  continued  into  it ; but  this  is  a point  very  difficult  to  determine, 
as  the  portio  dura  is  a compact  nerve,  and  not  so  fasciculated  as 
some  others  are.  However  this  may  be,  it  is  very  reasonable  to 
suppose  that  the  chorda  tympani  is  a branch  of  the  fifth  pair,  as  it 
goes  to  join  another -branch  arising  from  the  same  trCink.* 


20.  CROONIAN  LECTURE  ON  MUSCULAR  MOTION,  NO.  I. 

FOR  THE  YEAR  1776. 

[Read  before  the  Royal  Society,  by  Mr.  John  Hunter,  F.R.S.f] 

A SELF-MOVING  powei’  is  such  a phenomenon  as  must  call  up  the 
attention  of  the  thinking  mind  (w'hile  ignorant  of  the  cause) ; and 
when  that  very  mind  is  connected  wiffi  this  power  it  becomes  still 
more  interested. 

This  power  of  motion  was  first  discovered  to  be  inherent  in  parts 
of  an  animal  body  of  a certain  construction,  called  muscles.J  This 
construction  appeared  to  be  a composition  of  fibres,  which  w'ere 
called  muscular : and  motion  was  supposed  to  be  produced  by  these 
contracting  in  length,  and  all  the  varieties  of  motion  in  an  animal 

* [This  is  a point  which  it  is  undoubtedly  very  difficult  to  decide  by  dissection 
of  the  parts  in  the  human  body.  Cloquet,  Hirzel,  and  Majendie  describe  the 
chorda  tympani  according  to  the  supposition’  of  Hunter.  In  the  horse  and  calf, 
how.ever,  where  the  portio  dura  is  less  dense  in  its  structure,  the  Vidian  branch 
of  the  fifth  may  be  distinctly  seen  crossing  that  nerve  after  penetrating  its  sheath, 
and  separating  into  many  filaments,  with  which  filaments  of  the  seventh  nerve 
are  blended,  and  a ganglion  formed  by  the  superaddition  of  gray  matter ; the 
chorda  tympani  is  here  continued  partly  from  this  ganglion,  partly  from  the 
seventh  or  portio  dura.] 

f [In  Home’s  Account  of  the  Life  i of  John  Hunter,  prefixed  to  -the  treatise 
‘ On  the  Blood,  Inflammation,  and  Gunshot  Wounds,’  1794,  p.  xxviii.,  is  the 
following  passage : 

“ Besides  the  papers  which  he  presented  to  that  learned  body  (the  Royal 
Society),  he  (Mr.  Hunter)  read  six  Croonian  Lectures  upon  the  subject  of  mus- 
cular action,  for  the  years  1776,  1777,  1779,  1780,  1781,  1782.  In  these  Lec- 
tures he  collected  all  his  observations  upon  Muscles  respecting  their  powers  and 
effects,  and  the  stimuli  by  which  they  are  affected  ; and  to  these  he  added  com- 
parative observations  upon  the  moving  powers  of  Plants.  These  Lectures  were 
not  published  in  the  Philosophical  Transactions ; for  they  were  withdrawn  as 
soon  as  read,  not  being  considered  by  the  author  as  complete  dissertations,  but 
rather  as  materials  for  some  future  publication.”] 

X [Both  Aristotle  and  Hippocrates  were  ignorant  of  the  function  of  the  muscu- 
lar fibre : the  important  discovery  that  the  animal  motions  were  performed  by  the 
muscles  is  attributed  to  Lycus  of  Macedon,  who  wrote  a voluminous  work  bn 
Myology.  It  is  certain  that  the  use  of  the  muscles  was  known  to  Herophilus, 
since  he  is  quoted  by  Galen  as  having  spoken  of  the  happy  disposition  of  the 
muscles  for  the  movement  of  the  limbs.  To  Herophilus  belongs  the  honour  of 
having  first  discovered  in  the  nerves  the  organs  of  sensation  and  of  voluntary 
motion.] 


212 


' HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  most  complicated,  to  be  the  result  of  the  manner  in  which  these 
fibres  were  disposed. 

ft  is  no  wonder,  then,  that  the  mode  in  which  a muscular  fibre 
produces  motion  has  been  esteemed  an  inquiry  not  unworthy  the 
attention  of  the  greatest  philosophers,  and  has  almost  universally 
been  one  of  the  principal  researches  of  the  physiologist;  especially 
when  we  consider  that  the  substance,  called  muscular,  alone  con- 
stitutes the  largest  part  of  most  animals  ; and  indeed  many  are 
wholly  composed  of  it. 

The  inquiries  into  tlie  nature  of  self-motion  have  been  principally 
confined  to  animals  ; most  probably  from  the  power  in  them  being 
more  conspicuous,  which  almost  prevented  its  being  taken  notice  of 
in  any  other  substance  whatever.  Inquiries  into  nature  have,  how- 
ever, become  less  confined,  and  experiments  and  observations  have 
induced  men  to  leave  the  beaten  track  of  others,  and  take  their  ob- 
servations from  nature  herself;  by  which  means  a self-moving 
power  has  been  observed  and  universally  allowed  in  vegetables. 
And  this  principle,  upon  investigation,  appears  now  to  be  as  much 
a property  in  vegetables  as  in  animals ; and  in  such  cases  where 
the  functions  and  uses  are  the  same  in  both,  it  is  perhaps  as  con- 
siderable in  vegetables  as  animals.  But  where  they  are  dissimilar 
in  their  actions,  and  the  uses  arising  out  of  these  actions  are  also 
different,  it  is  reasonable  to  suppose  the  quantity  of  action  will  vary ; 
and  such  difference  must  frequently  occur  in  both  animals  and 
vegetables.  In  animals  a considerable  part  of  this  motion  is  called 
muscular ; in  vegetables  it  has  not  yet  got  a name. 

The  immediate  cause  of  motion  in  all  vegetables  is  most  probably 
the  same,  and  it  is  probably  the  same  in  all  animals;  but  how  far 
they  are  the  same  in  both  classes  has  not  yet  been  determined. 
But  I think  it  will  appear,  in  the  investigation  of  this  subject,  that 
vegetables  and  animals  liave  actions  evidently  common  to  both,  and 
that  the  causes  of  these  actions  are  apparently  the  same  in  both  : 
and  most  probably  there  is  not  an  action  in  the  vegetable  which 
does  not  correspond  or  belong  to  the  animal,  although  the  mode  of 
action  in  the  parts  may  not  be  the  same,  or  muscular,  in  both. 

There  appeal’,  however,  to  be  actions  in  animals  which  are 
peculiar  to  them  ; these  make  them  more  complicated,  and  in  them 
another  stimulus  to  action  is  superadded,  evidently  for  that 
purpose.* 

* [The  actions  here  alluded  to  are  the  voluntary,  which  are  consequent 
upon  an  act  of  sensation,  and  are  the  result  of  a determination  or  stimulus  derived 
from  the  braini  The  action  in  the  muscle  produced  by  this  stimulus  is,  how- 
ever, essentially  the  same  as  is  produced  by  mechanical  or  chemical  stimuli  ap- 
plied to  the  muscle  out  of  the  body,  or  as  takes  place  in  the  muscle  involuntarily 
as  in  sleep,  or  when  an  animal  is  stimulated  while  in  a state  of  hybernation,  or 
immediately  after  decapitation. 

Instead  therefore  of  saying  that  animals  have  actions  of  the  moving  powers 
peculiar  to  themselves,  it  is  more  correct  to  express,  with  reference  to  the  volun- 
tary actions,  that  they  have  parts  superadded,  for  the  purpose  of  exciting  the 
actions  of  the  moving  powers,  which  the  vegetable  has  not,  viz.,  the  nerves. 
It  is  true  that  the  actions  of  the  moving  powers  of  an  animal,  whether  autoraattG 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


213 


All  actions  may  be  considered  of  two  kinds,  immediate  and 
secondary. 

The  first  is  an  action  of  the  part  itself,  having  no  relation  to  any- 
thing else  ; as  action  in  a muscle,  or  elasticity  in  a spring. 

• The  second  may  be  divided  into  two  kinds, — first,  where  this 
action  has  an  effect  upon  some  other  part,  or  moves  it,  which  is  the 
ultimate  effect,  as  the  heart  moving  the  blood  by  contracting, — 
secondly,  where  the  action  is  applied  to  some  other  body  adapted 
for  a particular  motion,  which  is  to  produce  the  ultimate  effect, 
such  as  the  muscles  of  a joint. 

We  may  in  general  observe,  from  what  we  know  of  motion  or 
action  in  matter,  that  it  is  always  preceded  by  something  which 
we  call  the  cause  ; and  that  the  immediate  cause  is  an  irresistible 
impulse  to  action,  which  action  becomes  the  effect.  A body  endowed 
with  the  power  of  self-motion  is  under  the  same  influence  of  im- 
pulse as  matter  in  general : it  cannot  move  without  an  intermediate 
cause  for  its  motion. 

Self-motion  may  be  of  three  kinds  in  the  more  perfect  animals. 
The  first  is  where  the  motion  is  excited  by  a cause  Trom  within  the 
animal  itself,  and  is  employed  in  the  oeconomical  operations  and 
functions  of  the  machine,  and  with  the  materials  the  machine  is 
already  m possession  of,  which  are  only  made  use  of  in  the  growth 
of  parts,  secretion  of  fluids,  &c.  The  second  is  where  motion  is 
excited  from  an  internal  cause,  and  is  employed  in  particular 
functions  and  operations,  but  where  such  materials  used  are  out  of 
the  body  ,•  as  in  those  excited  inconsequence  of  hunger  and  thii’st, 
the  passion  between  the  sexes,  &c.  The  third  is  where  motion  is 
excited  by  external  stimuli,  and  where  whole  parts  are  put  in  mo- 
tion : as  where  the  sight  or  voice  of  a person  excites  one  to  approach 
him ; the  application  of  a medicine  which  excites  vomiting,  &c. 
We  can  have  no  other  idea  of  these  motions  in  animals  but  that 
they  are  muscular:  and  as  the  two  first  of  these  actions  exist  in 
vegetables,  it  is  natural  to  suppose  that  there  is  a similarity  in  the 
cause  which  produces  the  same  final  intention,  although  the  same 
mode  of  action  or  a similar  power  is  not  made  use  of  to  pro-, 
duce  it. 

These  immediate  causes  of  action  in  an  animal  are  called  stimuli, 
and  the  capability  in  parts  for  action  is  termed  irritability ; but 
such  a definition  is  too  confined  for  the  numerous  actions  excited 
in  an  animal  body. 

The  word  stimulus  is  pretty  well  determined  in  its -signification ; 
it  is  an  incitement  to  an  action  of  a proper  or  salutary  nature  : but 
the  calling  a part  capable  of  being  stimulated  an  irritable  part, 
weakens  the  idea  of  the  stimulus  being  the  cause  of  the  action  ; and 
indeed  the  expression  of  a part  being  ii’ritated  conveys  a different 
meaning  from  w'hat  would  be  annexed  to  the  effect  produced  by  a 

or  voluntary,  are  different  from  those  which  produce  the  motions  of  parts  in 
vegetables,  as  explained  in  the  notes,  pp.  216,  222  ; but  the  observations  in  the 
text  refer  only  to  the  voluntary  actions.] 


214 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


stimulus.  I would  therefore  define  a ‘ stimulus’  to  be  the  cause  of 
an  increased  natural  action  ; and  an  ‘ irritation’  to  be  the  cause  of 
an  unnatural,  disagreeable,  or  diseased  action. 

Vegetables  as  well  as  animals  have  their  motions  produced  by 
these  causes,  and  are  subject  to  the  very  same  laws.  A stimulus, 
or  excitement  to  actions  of  a salutary  or  proper  kind  is  simple,  and 
depends  on  the  original  mode  of  action,  or  the  original  laws  of  the 
vital  oeconomy,  and  the  action  only  changes  in  some  degree  as  the 
properties  of  the  matter  which  stimulates  changes.  An  irritation 
or  excitement  to  morbid  action  is  according  to  the  susceptibility  of 
the  body  or  part  which  is  to  be  excited  to  action,  and  alters  ac- 
cording to  the  power  of  the  irritating  matter,  combined  with  the 
various  susceptibilities  of  different  animals  and  parts  for  irritation ; 
for  different  animals  and  parts  have  different  modes  and  powers  of 
receiving  the  same  power  of  irritation. 

In  the  more  perfect  animals  we  have  the  senses,  or  parts  so  con- 
structed as  to  be  impressed  by  the  various  properties  of  matter, 
and,  as  it  were,  adapted  to  these  properties  alone.  These  are  con- 
nected together’  by  the  brain,  or  common  sensorium,  which  is  com- 
mon to  the  whole  of  the  sensitive  powers:  to  and  from  the  brain 
pass  the  nerves,  or  conductors  of  sensation  and  voluntary  stimulus. 
But  as  animals  become  more  and  more  imperfect,  the  senses,  or 
parts  constructed  so  as  to  be  impressed  -by  the  properties  of  matter, 
become  fewer,  and  the  common  sensorium  less  perfect.  There 
appear,  to  be  animals  entirely  deprived  of  these  parts  or  senses,  and 
consequently  having  neither  brain  nor  nerves.*' 

These  senses  give  us  intelligence  of  the  various  properties  of 
matter,  from  whence  we  derive  our  acquired  actions,  and  have 
been  naturally  led  to  suppose  that  there  were  no'  other  causes  of 
action  in  an  animal  body. 

The  eye  gives  us  at  once  the  shape  or  limits,  and  the  various 
effects  of  the  reflection  of  light  from  bodies  at  a distance;  the  first 
of  which  could  not  be  sufficiently  eflected  by  the  sense  of  touch,  and 
the  second  we  could  not  have  had  the  least  idea  of,  the  commoa 
powers  of  touch  not  being  sufficiently  acute.  • 

The  ear  is  adapted  to  receive  the  vibrations  of  air,  giving  us 
intelligence  of  bodies  at  a distance. 

The  nose  is  adapted  for  smelling,  giving  us  the  odorous  proper- 
ties of  the  m.atter  of  which  bodies  at  a distance  are  composed. 

The  tongue  is  adapted  to  tasting,  giving  us  a property  in  matter 
different  from  any  discovered  by  the  sense  of  touch. 

The  sense  of  touch  gives  us  a vast  variety  of  information 
respecting  the  form,  construction,  density,  &c.,  of  bodies.  In  giving 

* [Mr.  Hunter  nevertheless  appears  subsequently  to  have  believed  that  the 
animals  here  alluded  to,  the  Acriia  of  modern  naturalists,  had  something  similar 
to  the  materials  of  the  brain  diffused  through  the  body;  and  that  every  other 
principle  or  elementary  tissue,  as  the  muscular  fibre,  was  diffused  through  the 
whole,  making  every  part  alike  contractile  and  stimulable,  as  in  the  fresh-water 
polype.  Hydra  viridis,^ 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION.  S15 

US  form  and  construction  it  is  somewhat  similar  to  the  eye ; but  it 
is  obliged  to  run  over,  the  whole  for  this  intelligence,  whereas  the 
eye  takes  in  a larger  scope  of  this  intelligence  at  once.  However, 
even  the  eye  is  obliged  to  do  the  same  thing  where  the  object  is  too 
large,  or  w'here  it  is  examining  minutely. 

None  of  these  senses  are  affected  by  a stimulus  or  an  irritant, 
although  either  the  one  or  the  other  may  be  carried  so  far  as  to 
produce  sensation.  This,  however,  is  not  a necessary  effect,  unless 
the  stimulus  or  irritant  is  the  immediate  object  of  sensation;  as  the 
stimulus  of  light  to  the  eye,  or  the  irritation  of  too  much  light  to 
the  eye. 

These  organs  of  sense  are  parts  constructed  for  sensation,  and 
those  animals  that  are  endovved  with  all  of  them  must  be  the  most 
sensible  ; and  those  that  are  entirely  deprived  of  them  must  be 
wholly  insensible  to  every  impression  arising  from  the  different 
modifications  or  external  influence  of  matter. 

The  animals  which  receive  no  intelligence  from  external  objects 
have  their  actions  arising  out  of  immediate  stimuli  and  irritants,* 
and  their  consequent  sympathies,  which  last  extend  to  the  action 
beyond  the  part  of  impression.  The  perfect  animals  in  some  in- 
stances seem  also  to  be  under  some  general  power  or  externa! 
influence,  not  referrible  to  any  one  sense  or  all  of  them  taken 
together:  it  is  a general  observation  that  many  animals  go  into 
shelter  before  a storm  comes  on,  and  before  any  of  the  particular 
senses  can  be  effected.  Many  people  are  weather-wise,  as  it  is 
vulgarly  called,  and,  like  the  brutes,  are  sometimes  previously 
apprised  of  the  ensuing  change.  Many  sleep  soundest  in  a storm, 
especially  when  attended  with  thunder. 

The  natural  salutary  actions,  arising  from  stimuli,  take  place 
both  in  animals  and  vegetables,  and  may  be  divided  into  three 
kinds. 

The^?'st  kind  of  action,  or  self-motjon,  is  employed  simply  in  the 
(Economical  operations,  by  which  means  the  immediate  functions 
are  carried  on,  and  the  necessary  operations  performed,  with  the 
materials  the  animal  or  vegetable  is  in  possession  of,  such  as  growth, 
support,  secretion,  &c.  The  blood  is  disposed  of  by  the  actions  of 
the  vessels,  according  to  their  specific  stimulus,  producing  all  the 
above  effects.  The  juices  of  a plant  are  disposed  of  according  to 
the  different  actions  of  the  sap-vessels,  arising  also  from  their  spe- 
cific stimulus,  which  is  different  from  that  of  blood-vessels,  but 
equally  produces  growth:  but  a vine  will  grow  twenty  feet  in  one 
summer,  while  a whale  probably  does  not  grow  so  much  in  as 
many  years.f 

The  second  kind  of  action  is  in  pursuit  of  external  influence,  and 
arises  from  a compound  of  internal  and  external  stimulus  ; it  is  ex- 

[i.  e.  Of  stimuli  which  do  not  produce  action  through  the  medium  of  the 
brain.] 

f [The  insensible  organic  contractility  of  Bichat  corresponds  with  the  kind  of 
action  which  Hunter  here  defines.] 


S16 


HUNTER  ON  THE  ANIMAL  CCCONOMY. 


cited  by  the  state  of  the  animal  or  vegetable,  which  gives  the  stimu- 
lus of  want,  and,  being  completed  by  external  stimulus,  procures 
the  proper  supplies  of  nourishment.  It  produces  motions  of  whole 
parts  : thus  we  see  the  Hedysarum  gyrans  moving  its  lesser  foliola. 
This  is  an  action  apparently  similar  to  breathing  in  animals,  though 
perhaps  it  does  not  answer  the  same  purpose;  yet  there  is  an 
alternate  motion  in  both.  The  cirriferous  plants,  or  those  bearing 
tendrils  or  claspers,  requiring  to  be  supported  by  other  bodies,  as 
the  passion-flower,  briony,  vine,  &c.,  stretch  out  their  tendrils  as  it 
were  at  random,  moving  them  slowly  in  various  directions.  They 
are  to  lay  hold  of  any  substance,  that  may  be  within  their  reach 
that  can  support  them,  and  when  they  come  in  contact  with  a body 
on  that  side  where  their  power  of  motion  is  greatest  they  begin  to 
bend  in  that  direction,  grasp  it,  and  continue  turning  round  Jt.  We 
see  motions  of  the  same  kind  in  the  stems  of  \\\e,  PlantcB  volubiles ; 
some  of  these  turn  to  the  left,  as  the  Lonicera,  Humulus,  &c. ; some 
to  the  right,  as  the  Clitoria,  Convolvulus,  &c.  They  are  directed 
in  this  course  by  a lateral  inclination,  which  takes  place  only  on 
one  side,  they  having  little  or  no  power  of  action  on  the  other. 
Those  which  have  one  mode  of  action  pursue  that  principally ; but 
if  prevented  from  doing  it,  their  action  then  varies.  In  the  vine  and 
other  plants  the  action  of  the  tendrils  is  in  different  directions ; and 
they  may  be  seen  at  one  time  stretched  out  on  one'side  of  the  stem, 
and  in  twenty-four  hours’  time  on  the  opposite  side  ; and  some  time 
after  in  the  direction  of  the  stem  itself,  or  in  the  very  contrary  di- 
rection. These  actions  arise  equally  from  stimulus  ; it  requires, 
however,  different  powers  of  action,  arising  from  such  stimulus,  to 
produce  these  effects  in  different  plants.*  The  random  action  of 
the  polypus  is  of  the  same  kind  as  those  of  plants.  It  elongates 
itself  and  throws  out  its  tentacula,  moving  them  in  various  direc- 
tions to  catch  food ; the  use  of  this  action  to  the  animal,  however, 
is  immediate,  and  therefore  quicker  than  those  above  described.f 

. ♦ [In  the  plants  of  the  genus  Cuscuia  the  tendrils  will  only  twine  around  other 

living  plants,  which  shows  that  the  phenomena  of  climbing  plants  are  not  expli- 
cable simply  by  supposing  that  the  inclination  of  the  extremities  of  the  tendrils 
or  stems  towards  one  side  is  a necessarily  inherent  law  of  their  growth,  but  that 
it  is,  as  Hunter  regards  it,  an  action  dependent  on  stimulus,  which,  in  the  case  of 
the  Cuscuia,  would  seem  to  be  a species  of  organic  affinity.] 

f [In  comparing  the  motions  of  a polype  with  those  of  a plant,  the  following 
difference  must  be  borne  in  mind  : the  motions  of  a plant,  like  those  of  the  parts 
of  an  animal  after  their  communication  with  the  brain  has  been  cut  off,  are  in- 
variably the  result  of  external  stimulus;  they  follow,  as  it  were  mechanically, 
some  appreciable  change  in  the  surrounding  external  circumstances  or  influences, 
— it  may  be  alteration  of  temperature,  difference  of  light,  the  application  of  a 
chemical  or  mechanical  stimulus;  or,  in  an  animal,  loss  of  blood,  &c.  But  who- 
ever observes  the  actions  of  a Jiving  polype  will  see  that  although,  for  the  most 
part,  they  may  be  traced  to  an  external  cause  or  stimulus,  yet  that  one  or  more  of 
the  tentacula  are  occasionally  extended  or  retracted  without  the  slightest  appre- 
ciable change  in  any  of  the  external  circumstances  under  which  the  animal  exists. 
These  motions  evidently  result  from  an  internal  impulse,  and  1 would  refer  them  to 
the  presence,  in  the  polype,  of  an  organic  element, — the  nervous  matter, — which 


GROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


217 


The  third  kind  of  motion  is  from  external  stimulus,  and  consists 
principally  of  the  motion  of  whole  parts,  which  is  not  inconsiderable 
in  vegetables,  as  in  the  Dioncea  muscipula  and  Mimosa  pudica  is 
very  evident ; for  the  first,  upon  being  touched,  closes  up,  and  as 
it  were  confines  the  stimulating  cause  ; the  second  bends  its  leaves, 
from  external  stimulus.  This  kind  of  motion  is  very  strongly  illus- 
trated in  the  Tragopogon,  Calendula  pluvialis,  and  many  other 
plants,  which  shut  up  their  flowers  either  towards  night  or  when 
rain  comes  on  ; and  in  others  of  different  genera  which  open  in  the 
evening,  and  shut  up  on  the  approach  of  the  sun,  as  different  species 
of  the  Convolvulus,  Mirabilis,  &c. ; and  in  almost  the  whole  class 
Diadelphia,  w'hich  chiefly  consists  of  the  winged-leaved  plants, 
which  shut  up  their  foliola  towards  night,  not  expanding  them  till 
morning,  which  is  called  by  Linnaeus  the  sleep  of  plants ; and  in 
the  motion  of  the  footstalk  of  the  leaf  of  an  inverted  plant,  which 
twists  so  as  to  bring  the  surface  of  the  leaf  naturally  uppermost  to 
its  natural  position,  which  is  remarkable  in  the  vine,.where  there  is 
evidently  an  apparatus  for  motion,  although  not  a joint. 

- These  actions  are  similar  to  what  arise  in  many  animals  from 
external  stimulus,  more  especially  those  not  endowed  with  sensa- 
tion, and  also  to  the  actions  of  many  parts  of  animals  which  do  not 
appear  to  be  directed  or  stimulated  by  the  brain  and  nerves;  as  the 
actions  of  a polypus,  which  has  no  brain,  and  the  peristaltic  motion 
of  the  intestines  in  the  more  perfect  animals,  which  does  not  arise 
from  the  stimulus  of  the  brain  and  nerves.* 

is  wanting-  in  the  vegetable;  even  in  that  plant,  which,  from  the  energy  of  its 
excitability,  has  been  erroneously  called  sensitive.  There  is  also  an  essential 
difference  in  the  nature  of  the  motion  itself  of  the  Mimosa  and  Hydra,  If  we 
touch  one  of  the  feelers  of  the  polype  it  recedes  from  the  irritant  by  a true  con- 
traction of  the  part  within  itself;  which  contraction  appears  to  result  from  the 
injury  experienced  by  that  part  of  the  nervous  system  which  is  disseminated 
through  the  feeler  touched.  In  the  case  of  the  Sensitive  plant  there  is  nothing 
like  that  contraction  of  the  part  touched,  but  only  an  articular  plication  of  the 
neighbouring  part  without  any  of  the  dimensions  of  the  irritated  leaf  being 
altered.] 

* [The  more  just  comparison  of  the  motions  of  plants  adduced  in  the  text  would 
be  with  those  automatic  actions  of  whole  parts  which  take  place  in  animals,  but 
which  result  from  the  power  possessed  by  the  central  axis  of  the  nervous  system, 
or  any  part  of  it,  to  transmit  the  action  of  an  excitable  nervous  fibril  to  the  ex- 
citing one  with  which  that  central  axis  or  part  brings  it  into  communication:  I 
apply  the  terms  excitable  and  exciting  to  the  nervous  fibres  with  reference  to  their 
intermediate  relation,  as  to  the  muscular  fibre  and  the  external  stimulus  to  its 
contraction.  The  excitable  fibres  are  those  usually  termed  sensitive ; the  exciting 
fibres  those  usually  termed  motive.  When  the  communication  between  the  ex- 
citable nervous  fibre  and  the  brain  is  entire  or  uninterrupted,  the  latter  may  take 
cognizance  of  the  excitement  and  sensation  be  produced.  When  the  exciting 
nervous  fibres  of  muscular  motion  are  in  connection  with  the  brain,  the  will, 
through  the  brain,  may  excite  them  to  action,  and  this  act  of  the  brain  may  be 
felt.  The  essential  character-,  therefore,  of  the  actions  of  the  brain,  whether  as  a 
recipient  or  transmitter  of  impressions,  is  consciousness  of  the  action.  But  this 
property  of  consciousness  is  not  possessed  by  the  spinal  chord,  probably  no!  by 
the  medulla  oblongata.  Whenever,  therefore,  an  impression  received  by  an  ex- 
citable nervous  fibre  is  transmitted  through  the  unconscious  part  of  the  central 


218 


HUNTER  ON  THE  ANIMAL  tECONOMY. 


The  apparent  difference  in  these  actions  would  in  many  cases 
induce  us  at  first  to  believe  they  were  produced  by  different  prin- 
ciples ; as  in  many  species  of  the  same  genus  of  plants  some  open 
their  flowers  in  the  day,  others  at  night  (as  in  the  Mesembryanthe- 
mum,  or  fig-marigold),  similar  to  that  which  is  the  oeconomy  of 
some  animals,  as  in  many  species  of  the  same  genus  of  moths 
{Phalaina,  Linn.),  some  fly,  seek  their  food,  and  procreate  in  the 
day ; while  others  are  inactive  and  fixed  to  one  spot,  without 
apparent  motion,  all  day,  but  on  the  approach  of  night  become  all 
at  once  animated,  fly  abroad,  seek  their  food,  and  procreate.  These 
actions,  are  nevertheless,  produced  by  one  and  the  same  cause. 

The  owl  and  hawk  are  similar  in  their  food,  yet  dissimilar  in 
their  times  of  catching  it:  hunger  is  the  first  stimulus,  animal 
food  is  the  second  ; light  stimulates  the  one  to  motion,  darkness 
the  other.*  The  action,  however,  in  both  arises  from  the  same 
principle. 

These  three  kinds  of  motion  in  plants  are  influenced  by  various 
circumstances,  and  sometimes  are  all  totally  suspended.!  This  is 

axis  to  the  exciting  fibre  of  muscular  motion,  the  latter  phenomenon  is  unaccom- 
panied with  consciousness  or  sensation.  That  the  spinal  chord,  or  any  segment 
of  it,  possessed  the  power  of  transmitting  an  impression  from  an  excitable  to  an 
exciting  nervous  fibre,  has  been  known  and  admitted  as  a fundamental  fact  in 
physiology  since  the  experiments  of  Whytt,  Blane,  and  Mayo.  To  the  latter 
physiologist  we  are  more  especially  indebted  for  the  most  decisive  experiments 
in  proof,  and  the  clearest  enunciation,  of  this  property  of  the  central  nervous  axis. 
Recently  the  automatic  animal  motions  resulting  from  this  property  have  been 
grouped  together  more  extensively  than  had  before  been  done,  and  the  morbid  phe- 
nomena resulting  from  them  ably  traced  out  by  Dr.  M.  Hall.  But  I cannot  perceive 
the  necessity  of  a distinct  class  of  excitable  nervous  fibres  for  transmitting  an 
impression  to  the  motive  fibre  through  the  medium  of  the  spinal  chord  and  brain, 
and  of  another  class  of  nervous  fibres  for  transmitting  an  impression  to  the  motive 
fibre  through  the  medium  of  the  spinal  chord  alone;  still  less  can  I perceive  the 
necessity  for  one  class  of  exciting  or  motive  fibres  for  transmitting  the  stimulus 
to  the  muscular  fibre  from  the  brain  and  spinal  chord,  and  of  another  and  distinct 
class  for  transmitting  a stimulus  received  from  tire  spinal  chord  independetitly  of 
the  brain.  It  remains  to  be  seen  whether  anatomy  will  establish  the  existence 
of  these  four  classes  of  nervous  fibres,  which,  so  far  as  1 understand  Dr.  Hall’s 
hypothesis  of  the  reflex  function,  are  called  in  to  'account  for  the  voluntary  and 
automatic  and  muscular  motions.  There  is  not,  however,  a single  phenomenon 
of  automatic  motion  in  parts  supplied  by  spinal  nerves  which  may  not  beaccounted 
for  on  the  demonstrated  property  of  the  central  axis  to  transmit  impressions  from 
the  excitable  to  the  exciting  nerves  at  any  part  where  they  are  connected  to  it,  inde- 
pendently of  the  rest:  and  I am  at  a loss  to  understand  why  impressions  so  received 
by  the  spinal  chord  should  not  also  be  transmitted  to  the  brain  (its  contin\iity 
with  that  organ  being  uninterrupted),  without  the  necessity  of  supposing  a class 
of  nervous  fibres  for  conveying,  in  this  case,  the  impressions  to  the  spinal  chord, 
distinct  from  a second  class  which  are  supposed  to  transmit  to  the  motive  fibres 
those  impressions  which  are  not  afterwards  propagated  to  the  brain.  It  would 
appear  from  the  text  that  Hunter  supposed  that  the  animal  motions  which  are 
unaccompanied  by  consciousness  were  altogether  independent  of  the  nerves  ; but 
they  can  truly  be  stated  to  be  only  independent  of  the  brain.] 

* It  may  be  supposed  that  there  is  a physical  cause  for  the  one  seeing  only  in 
the  day,  the  otlier  only  at  night;  but  it  is  having  a much  more  enlarged  idea  of 
an  animal  to  suppose  that  the  senses  are  adapted  to  the  first  principle  than  the 
first  principle  to  the  senses. 

I Similar  to  drowned  people. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


219 


generally  produced  by  cold,  and  shows  them  to  be  influenced  by 
the  seasons;  often  this  cessation  takes  place  when  much  weakened 
by  transplanting,  &c.  I have  kept  a fir  alive  for  three  years  with- 
out the  least  growth. 

The  second  and  third  kind  of  actions  commonly  take  place  only 
when  the  first  kind  of  action  is  in  full  vigour,  because  the  first  must 
produce  the  only  parts  which  are  capable  of  the  second  and  third ; 
and  these  two  last  can  only  be  of  service  to  the  first  when  it  is  in 
full  force,  nourishing  the  vegetable  and  performing  the  action  of 
propagation. 

These  actions  are  almost  entirely  suspended  in  some  animals 
from  cold,  they  being  in  this  respect  subject  to  seasons  as  well  as 
plants.  This  is  most  remarkable  in  the  simplest  in  their  construc- 
tion, and  becomes  less  and  less  so  in  the  more  complicated,  they 
being  better  adapted  to  the  various  seasons. 

The  first  of  these  kinds  of  action  is  small  and  insensible,  although 
its  effects  are  great.  The  second  is  considerable  in  both  vegetables 
and  animals,  but  most  so  in  animals.  The  third  is  almost  peculiar 
to  animals,  as  there  are  very  few  vegetables  visibly  affected  by 
external  stimulus,  while  all  animals  seem  to  be  so. 

The  variety  of  motions  is  greater  in  animals,  and  more  purposes 
are  answered  by  them,  which  constitutes  the  great  difference 
between  the  actions  of  a vegetable  and  an  animal ; for  those  powers 
in  an  animal  not  only  move  themselves,  but  also  other  parts  of  the 
same  body,  which  in  many  instances  are  so  mechanically  con- 
structed as  to  move  common  matter.  A remarkable  instance  of 
this  is  the  human  hand ; and  it  is  by  this  means  all  our  various 
operations  on  the  matter  of  this  globe  are  performed. 

The  first  kind  of  action  appears  to  be  stronger  in  its  power, 
although  less  in  quantity,*  in  vegetables  than  in  animals ; for  a 
small  vine  was  capable  of  sustaining  and  even  of  raising  a column 
of  sap  43  feet  high,t  while  a horse’s  heart  was  only  capable  of  sup- 
porting a column  of  blood  8 feet  9 inches  high:  both  of  which 
columns  must  have  been  supported  by  the  action  of  the  internal 
parts,  for  we  must  suppose  the  heart  equal,  or  nearly  so,  to  the 
strength  or  action  of  the  other  parts  of  the  vascular  system ; and 
when  we  consider  that  the  sap  of  the  tallest  tree  must  be  supported 
and  even  raised  from  the  root  to  the  most  distant  branches,  it  must 
appear  that  the  power  of  such  vegetables  far  exceeds  the  power  of 
any  animal,  and  indeed  it  is  such  as  the  texture  of  a vegetable  only 
can  support.  The  power  of  supporting  a leaf  erect  for  a whole 
day  is  as  great  an  effort  of  action  as  that  of  the  elevator  palpe- 
brarum muscle  of  tbe  eye  of  an  animal. 

If  we  consider  the  differences  in  the  oeconomy  and  the  mode  of 
life  of  vegetables  and  animals,  we  shall  find  the  increased  quantity 

• I make  a material  difference  between  the  power  and  the  quantity  of  action. 
Some  motions  may  be  very  small,  yet  act  with  great  force;  while  others  are  of 
considerable  extent,  although  very  weak. 

t Vide  Hale’s  Veg.  Statics,  vol.  i.,  p.  112,  Exp.  36. 


220 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


of  motion  of  the  three  kinds  above  mentioned,  and  the  increased 
povi-er  of  the  third  kind  in  animals  are  only  adapting  them  to  those 
differences. 

Locomotion,  for  the  purposes  of  procuring  nourishment,  con- 
course of  different  individuals  for  the  propagation  of  the  species, 
and  destruction  of  each  other,  are  the  chief  differences  in  animals. 
This  power,  however,  is  not  given  to  all  animals,  and  those  which 
are  deprived  of  it  have  their  motion  confined  to  the  procuring  food 
and  the  propagation  of  their  species.*  Many  of  these,  although 
with  great  impropriety,  have  been  considered  as  vegetables. 

To  see  if  the  actions  of  plants  were  affected  by  a continuation 
of  stimulus  similar  to  those  of  animals,  I rnade  the  following  ex- 
periments. 

As  I took  for  granted  that  the  analogy  could  go  no  further  than 
as  it  related  to  the  actions  produced  by  external  stimuli,  my  ex- 
periments were  only  on  such  plants  as  exhibited  actions  of  this 
kind. 

As  those  parts  of  plants  which  are  capable  of  the  second  and 
third  kinds  of  motion  are  in  general  small,  as  leaves,  tendrils, 
flowers,  &c.,  it  is  difficult  to  discover  the  mechanism  upon  which 
the  motion  depends:  the  sensitive  plant  is  probably  the  best  of  this 
kind  that  we  are  as  yet  acquainted  with. 

As  the  motion  of  the  petioli  is  confined  principally  to  one  part, 
and  that  differing  from  the  others  in  external  apipearance,  which 
difference  is  its  increased  thickness  and  uniformity  of  surface,  upon 
cutting  the  footstalk  longitudinally,  as  also  the  stem  on  which  it 
stands  through  its  whole  length,  the  following  appearances  may  be 
observed : — f 

For  the  purpose  of  making  my  experiments  I took  three  sensitive 
plants,  having  several  others  for  any  comparative  experiments 
which  might  be  thought  necessary.  I first  pitched  upon  one  leaf 
in  each  plant  which  was  capable  of  the  greatest  motion  of  collaps- 
ing and  erection  ; and  behind  each  of  these  leaves  a board  was 
placed,  on  which  was  marked  the  greatest  extent  of  the  two 
motions,  so  that  the  leaf  was  like  the  index  or  radius  of  an  arc. 

To  have  the  greatest  part  of  the  day  before  me^  I began  my 
experiments  at  eight  in  the  morning,  while  the  leaves  were  in  full 
expansion,  and  I continued  them  till  four  in  the  afternoon,  as  longer 
than  this  would  not  have  been  just,  for  they  begin  to  collapse  of 
themselves  between  five  and  six  o’clock. 

♦ [The  two  sexes  are  also  necessarily  united  in  the  same  individual,  as  in  all 
attached  and  pedicellate  animals,  from  the  Coralline  to  the  Barnacle,  and  in  many 
others  of  slow  motions.  See  note,  p.  71.] 

f [A  blank  in  the  manuscript  here  occurs,  which  leaves  us  ignorant  as  to  the 
result  of  Hunter’s  examination  of  the  structure  of  the  irritable  intumescence  at 
the  base  of  the  leaf-stalks  and  stalkletsof  the  Mimosa.  With  his  usual  sagacity, 
however,  he  rightly  refers  the  motive  power  to  this  ]>art,  and  it  has  been  the 
subject  of  much  diligent  and  minute  investigation  since  these  Croonian  Lectures 
were  read.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


221 


Comparative  Trials  of  the  Action  and  Relaxation  of  Three  Sensitive  Plants. 


o. 

u 

The  time. 

The  point  they  fell  to. 

The  times  they 
took  to  rise  in. 

1. 

8 o’cl’k  A.M 

f To  the  lowest  point,  ^ 
•?  and  became  sta-  > 
tionary.  y 

No.l 

Min. 

51 

No.  2 
Min. 

24 

No.  3. 
Min. 

32 

2. 

9^  A.M. 

rTo  the  lowest  point,  ^ 
< but  the  second  > 
C lower  down.  y 

77 

18 

38 

3. 

11  A.M. 

f The  second  & third  ^ 
lower  than  lowest  > 
( point.  y 

40 

30 

60 

4. 

12  Noon. 

Below  lowest  point. 

30 

30 

35 

5. 

40  min.  p.m. 

Below  lowest  point. 

60 

65 

30 

2 P.M. 

5 1st  only  below  low-  ) ' 
) est  point.  ^ 

45 

45 

45 

3 P.M. 

Ditto. 

45 

45 

45 

3^  P.M. 

Below  lowest  point.  ^ 

15 

15 

15 

The  point  to  which  they  rose 


pThe  1st  and  3d  rose 
I to  the  highest  point, 
the  2d  not  so  high, 
j and  then  became 
L stationary. 

(^The  3d  rose  to  the 
I highest  point,  the 
2d  and  1st  not  so 
high,  and  then  be- 
came stationary. 
f All  three  rose  to  with 
I in  a little  of  the 
highest  point,  and 
there  became  sta 
tionary. 

< All  three  within  a little 
( of  the  highest  point. 
fThe  2d  and  3d  to 

< highest  point,  the 
([  1st  not  so  high. 

Ditto. 

( 3d  to  highest  pointy 
^ the  1st  and  2d  not 
f so  high. 

f 1st  and  2d  to  highest 

< point,  3d  not 
r high. 


From  these  experiments  we  may  draw  the  following  conclusions  : 

That  there  is  no  fixed  time  for  the  leaves  of  any  of  the  plants  to 
move  through  its  course. 

That  they  are  less  affected  as  they  become  accustomed  to  the 
stimulus,  but  the  power  of  collapsing  is  increased  (although  not 
in  the  same  degree),  so  that  they  do  not  move  through  the  same 
arc. 

That  they  require  a stronger  or  quicker  stimulus  to  produce 
motion  after  being  some  time  accustomed  to  it,  which  was  evd- 
dently  seen  in  comparing  these  with  others  which  had  not  been 
stimulated. 

It  may  also  be  observed  that  when  these  plants  collapse  in  the 
evening  they  have  nearly  the  same  quantity  of  flexion  as  when 
roughly  touched  at  noon ; but  if  touched  after  they  have  collapsed 
from  the  effect  of  the  evening,  they  become  much  more  bent  than 
by  the  same  touch  at  noon.  This  would  seem  to  arise  from  a dis- 
position to  collapse  in  the  evening,  and  a power  of  increasing  that  • 
disposition  and  action  when  stimulated. 

20* 


222 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


Tlieir  collapsing  more  in  the  day,  and  erecting  themselves  less 
after  a repetition  of  such  actions,  may  assist  in  explaining  the  prin- 
ciple on  which  this  depends. 

Relaxation  in  Vegetables. 

There  is  an  action  in  plants  which  appears  to  be  the  contrary 
of  expansion;  it  may  be  considered  as  a relaxation,  or  an  action 
of  those  parts  antagonising  the  others  which  acted  through  the 
day,  or  at  other  periods,  and  takes  place  at  the  time  these  other 
parts  cease  to  act. 

This  action  has  hitherto  been  considered  as  analogous  to  sleep 
in  animals,  whereas  sleep  is  a total  loss  of  the  sensitive  principle 
and  all  the  actions  dependent  on  volition  for  the  time,  and  there- 
fore can  only  take  place  in  animals  endowed  with  sensation.*  It 
is  rather  a defect  in  the  animal  than  an  action  or  the  exertion 
of  a principle. 

This  action  of  relaxation  is  seen  in  the  sensitive  plant  when  the 
folioli  close  upwards  and  are  kept  bent  by  the  power  of  action  in 
the  flexors,  till  light  and  some  other  of  its  attendants  affect  it,  when 
the  extensors  begin  to  act,  and  this  action  of  the  flexors  ceases. 
The  footstalk  dropping  down  favours  the  idea  of  simple  relaxation  ; 
but  this  only  arises  from  the  position  of  the  plant,  for  if  turned  up- 
side down  it  still  bends  against  its  own  gravity.^ 

The  one  action  is  produced  by  the  stimulus  of  light,  the  other  by 
that  of  darkness;  for  if  the  sensitive  plant  is  kept  in  a dark  room  it 
will  keep  bent,  and  perhaps  as  long  as  it  lives;  and  if  one  part  of 
the  plant  is  kept  in  the  dark  and  the  other  in  the  light,  that  in  the 
dark  will  be  bent,  and  continue  so,  while  that  in  the  light  will  ex- 
pand itself.  • 

Light  and  darkness  become  stimuli  to  the  same  plant,  and  have 
much  more  influence  over  vegetables  than  could  at  first  be  ima- 
gined. Many  plants  only  grow  through  the  day,  others  only  grow 
after  it  is  dark. 

Sympathy  in  Vegetables. 

Sympathy  is  the  action  of  one  part  in  consequence  of  an  applica- 
tion being  made  to  another  part,  or  action  in  another  part. 

This  power  of  action  is  extended  to  few  plants,  and  even  in  these 
appears  to  have  little  variation.  . It  is  evident  in  the  sensitive  plant; 
for  if  one  of  the  little  leaves  be  wounded  at  its  termination  it  will 
collapse  immediately,  as  also  its  fellow  on  the  other  side.  This 
action  runs  through  the  whole  of  the  rachis  of  the  compound  leaves, 
the  leaves  bending  regularl}^  in  pairs.. 

* The  polypus  does  not  sleep. 

I [The  powers  which  produce  the  depression  and  elevation  of  the  leaf-stalk 
operate  in  a manner  precisely  the  reverse  of  the  flexor  and  extensor  muscles  in 
animals,  pushing  the  moving  part  from,  instead  of  pulling  it  towards,  the  fixed 
point.  See  Mayo’s  Physiology,  p.  9 et  icy.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


223 


If  it  is  a middle  foliole  that  is  wounded  the  same  thing  takes 
place  ; they  all  collapse  towards  the  foot-stalk,  but  seldom  towards 
the  extreme  end  of  the  leaf,  and  in  a little  time  the  rachis  is  inflected 
and  the  whole  leaf  drops  at  the  trunk.  It  may  be  remarked  that  a 
small  flexion  takes  place  towards  the  tip  ; but  this  principally  arises 
from  a disposition  in  the  folioles,  for  a middle  one  cannot  collapse 
without  pressing  or  folding  a little  on  the  one  next  to  it  towards  the 
end  of  the  leaf  which  stimulates  it  and  makes  it  collapse. 

It  is  evident  in  the  tendril  of  the  vine,  for  these  tendrils  generally 
divide  into  two,  near  their  ends:  these  two  going  out  from  the 
principal  trunk  in  different  directions,  if  one  lays  hold  of  any  body 
and  twines  round  it,  the  other  immediately  alters  its  direction  and 
gradually  approaches  the  same  body  till  it  comes  in  contact  with  it, 
and  then  bends  round  it  and  encircles  it.  This  motion,  hoVvever, 
is  very  slowly  performed. 

Sympathy  in  plants  is 'very  slow  in  producing  its  actions  ; the 
succession  of  stimuli  in  them  being  slow,  the  consequent  actions 
must  also  move  slowly  along. 

Plants  have  but  one  mode  of  sympathy,  which  arises  from 
stimulus.  Animals  with  no  brain  or  nerves  have  but  one  also. 
Those,  however,  endowed  * M'ith  sensation  have  three:  they  have 
one  mode  from  stimulus;  one  from  sensation,  and  one  compounded 
of  both. 

Sympathy  in  animals,  arising  from  stimulus  only,  is  slow,  as  in 
plants;  but  sympathy  from  sensation  is  often  very  quick. 

MOTION  IN  ANIMALS. 

Muscles  would  seem  to  act  by  vibration,  although  in  a strong 
healthy  man  they  are  so  short  as  not  to  be  observed ; yet  if  the 
muscles  are  made  to  act  beyond  their  powers  they  plainly  vibrate, 
■but  still  more  plainly  in  weak  constitutions. 

The  weaker  a muscle  is,  the  longer  would  seem  to  be  the 
vibrations,  for  if  a weak  person  holds  anything  out  in  his  hand  it 
shakes. 

In  paralytic  cases,  whenever  they  are  put  to  the  smallest  action, 
the  vibration  becomes  very  long,  and  the. less  the  action  the  shorter 
the  vibration. 

Fear  also  increases  the  vibration  in  proportion  as  it  weakens  the 
muscle.* 

* [The  first  part  of  Dr.  Wollaston’s  Croonian  Lecture  for  1809  is  devoted  to 
the  illustration  of  an  opinion  on  the  nature  of  muscular  motion,  corresponding 
with  that  which  Hunter  has  above  enunciated.  Dr.  Wollaston,  as  is  well-known, 
was  led  to  infer  that  each  act  of  contraction,  apparently  single,  consisted  in 
reality  of  a great  number  of  contractions,  repeated  at  short  intervals,  by  reflecting 
on  the  sound  perceived  upon  inserting  the  e.xtremity  of  the  finger  into  the  ear. 
This  sound,  which  resembles  that  of  carriages  at  some  distance  passing  rapidly 
over  a pavement,  is  not  perceived  when  the  force  applied  to  stop  the  ear  is  not 
muscular,  unless  the  action  of  some  distant  muscle  be  communicated  through 
some  medium  capable  of  conveying  its  vibrations.  From  experiment,  associated 


224 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  Causes  of  Action  in  Muscles. 

The  actions  of  muscles  have  been  hitherto  attributed  to  the  nerves 
as  a cause;  the  mode  of  action  of  the  nerves,  however,  not  being 
known,  most  physiologists  have  thought  themselves  obliged  either 
to  make  a new  hypothesis,  or  support  an  old  one  ; in  all  which 
they  make  it  mechanical,  depending  either  upon  the  motion  of  a 
fluid,  or  the  vibration  of  a solid,  or  vapour  ; but  there  is  not  a single 
known  fact  attending  the  nervous  system  which  could  either  give 
rise  to,  or  support,  these  hypotheses,  except  the  distance  between 
the  seat  of  the  will  and  a voluntary  muscle;  and  they  have  conse- 
quently been  such  as  few  thinking  men  could  adopt. 

As  the  brain  and  voluntary  muscles  are,  with  respect  to  our 
senses,  in  two  different  places,  and  are  connected  together  by  the 
nerves,  it  might  be  supposed  there  was  some  fluid  in  motion  that 
would  convey  the  impression  to  the  mind,  or  the  will  of  the  mind 
to  the  voluntary  muscles;  but  these  informations  are  very  probably 
the  eflects  of  sympathy. 

I am  afraid  we  can  go  no  further  in  the  investigation  of  the  cause 
of  the  action  of  muscles  than  by  observing  the  phenomena  which 
happen,  and  these  all  lead  us  to  one  cause  of  action. 

The  visible  external  cause  of  the  action  of  a muscle  is  called 
‘ stimulus,’  and  it  is  reasonable  to  suppose  that  all  causes  of  such 
action  are  similar.  This,  however,  may  admit  of  dispute,  the  heart 
certainly  having  no  visible  stimulus  for  its  motion,  except  the  being 
called  upon,  by  the  sympathy  which  subsists  between  the  combined 
powers  of  the  animal  (economy,  to  exert  itself  in  their  favour,  which 
will  not  account  for  the  heart's  motion  when  removed  from  that 
connexion. 

The  great  question  has  hitherto  been,  whether  a muscle  is  suscepti- 
ble of  impression  without  the  medium  of  a nerve,  or  whether  a nerve 
is  in  all  cases  necessary  to  its  being  called  into  action  ; for  a stimulus 
must  either  affect  the  nerve  which  affects  the  muscle,  or  the  muscu- 
lar fibre  itself  must  be  susceptible  of  immediate  impression  from 
the  stimulus. 

A muscle  would  appear  to  be  capable  of  being  affected  in  both 
ways,  for  many  animals  certainly  exist  without  nerves,  and  plants 
are  susceptible  of  stimulus  where  it  must  be  immediate,  they  never 
having  been  supposed  to  have  nerves.’^  It  is  also  evident  in  ani- 

Vi^ith  the  above  observation.  Dr.  Wollaston  concluded  that  the  vibratory  alterna- 
tions recur  between  twenty  and  thirty  times  in  a second,  varying  in  proportion  to 
the  degree  of  force  exerted  by  the  muscle  ; the  greatest  number  being  estimated 
at  thirty-five  vibrations  in  a second,  and  the'  lowest  at  fifteen.  The  more  obvious 
illustrations  of  this  mode  of  muscular  action,  presented  by  the  aged  and  infirm, 
are  also  erdduced  by  Dr.  Wollaston,  who,  without  doubt,  was  quite  unconscious 
of  the  conclusion  previously  drawn  by  Hunter  from  the  same  phenomena.] 

* [Those  who  admit  that  a muscle  is  susceptible  of  stimulns  only  through  the 
medium  of  the  nervous  matter  blended  with  its  substance,  do  not  scruple  to  ascribe 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


225 


mals  with  nerves  that  by  stimulating  a nerve  the  muscle  to  which 
it  goes  will  be  immediately  thrown  into  action,  the  nerve  becoming 
the  immediate  stimulant,  so  that  a muscular  fibre  may  be  stimulated 
by  a nerve  as  well  as  by  any  other  impression. 

The  modes  of  stimulating  a muscle,  will  be  different  according 
to  the  nature  of  the  animal  or  of  the  muscle.  In  the  more  simple 
animals  they  will  be  few,  increasing  as  the  animal  is  more  com- 
plicated. 

The  first  kind  of  stimulus  is  that  common  to  all  animals  and 
vegetables,  which  regulates  the  internal  machine,  producing  growth, 
preparing  the  parts  of  generation,  &c.,  &c. 

The  second  is  the  internal  stimulus,  which  respects  external 
matter  for  the  support  and  continuance  of  the  first,  as  that  pro- 
ducing breathing,  hunger,  the  desire  of  propagating  the  species; 
all  of  which  are  common  to  vegetables  as  well  as  animals,  and 
require  the  assistance  of  a third  kind  to  complete  the  action. 

Vegetables  are  supposed  with  great  reason  to  have  an  action 
analogous  to  breathing,  for  the  same  kind  of  air  which  kills  animals 
which  do  breathe,  certainly  kills  vegetables  also.*  Vegetables  im- 
bibe nourishment,  which  action  arises  from  the  same  stimulus  as  in 
animals.  They  also  require  the  stimulus  of  certain  operations  to  be 
performed  upon  them  by  external  matter  to  enable  them  to  propa- 
gate. This  external  matter  is  either  some  other  part  of  the  same 
plant,  as  in  the  Marchantia  polymorphia  calyce  decemfido,  which 
has  the  filaments  almost  constantly  in  motion  striking  the  antherae.t 

nervous  or  sensitive  globules  to  vegetables.  But  they  here  create  the  necessity 
which  an  .undemonstrable  organ  is  called  in  to  supply.  Now  the  more  simple 
and  philosophical  mode  ofconsidering  this  question  seems  to  be  to  examine  whether 
the  moving  organs  are  stimulated  in  any  new,  distinct,  and  additional  manner  in 
those  organized  beings  in  which  nerves  have  been  detected;  and  if  it  be  found 
that  they  all  manifest  spontaneous  actions, — motions  of  parts  independent  of  any 
external  stimulus, — a phenomenon  which  has  never  been  witnessed  in  any  plant, 
then  the  next  step  would  be  to  determine  by  experiment  the  relations  subsisting 
between  the  new  function  and  the  superadded  organ.  The  irritable  fibre  does 
not  contract  in  a different  manner  when  stimulated  by  the  will  than  when  stimu- 
lated mechanically  out  of  the  body  ; nerves,  it  is  true,  convey  impressions  which 
excite  action,  and  are  essential  to  the  application  of  the  voluntary  stimulus,  but 
not,  therefore,  to  the  muscular  contraction.  Hence,  when  wm  come  to  account 
for  the  cause  of  the  spontaneous  actions  in  animals  in  which  no  nerves  have  been 
detected,  v/e  are  justified,  by  analogy,  in  attributing  the  spontaneous  stimulus  to 
the  presence  of  undemonstrable  nervous  matter.  But  in  the  case  of  jdants,  if  we 
attribute  the  contractions  to  anything  but  the  irritability  of  the  moving  parts 
themselves,  we  must  first  hypothetically  assume  that  nerves  are  necessary  for  the 
action,  and  then  gratuitously  infer  their  existence.'  This,  however,  only  leads  to 
a greater  difficulty,  to  account,  viz.,  for  the  non-existence  of  spontaneous  motions 
in  those  organized  beings  to  which  nerves  are,  in  the  above  theory,  attributed.] 

* [As  azote,  hydrogen,  or  any  gas  deprived  of  carbon  and  oxygen ; for  though 
vegetables  in  health  and  sunshine  give  out  oxygen,  they  absorb  that  gas,  and  emit 
carbon,  but  in  less  proportion,  during  the  night.] 

f [In  the  barberry  the  filaments  supporting  the  mature  anther,  when  touched, 
bend  towards  the  germen.  In  the  tiger-lily  the  female  part  of  the  flower  is 
endowed  with  irritability,  and  the  style  bends  first  to  one  stamen,  then  to  another.] 


226 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  filaments  of  the  flosculm  of  the  thistle  produce  the  same  effect, 
or  it  is  done  by  some  foreign  stimulus,  as  the  wind,  driving  the 
pollen  of  the  male  plants  against  the  germina  of  females.^'  Most 
animals  perform  these  actions  themselves,  yet  in  both  animals  and 
vegetables  a similar  stimulus  is  necessary. 

The  third  kind  of  stimulus  is  from  external  or  extraneous  matter 
immediately  applied  to  the  part,  which  is  also  common  to  animals 
and  vegetables. 

The  fourth  kind  of  stimulus  arises  from  the  nerves,  which  we 
may  reckon  twofold ; one  in  consequence  of  the  nerves  being  im- 
pressed by  external  matter,  the  other  from  their  being  impressed  by 
the  brain,  or  sensorium. 

This  is  peculiar  to  animals,  many  of  them  receiving  intelligence 
from  without,  which  becomes  the  regulator  of  their  actions  towards 
that  matter  which  gives  the  intelligence.  This  leads  us  immediately 
to  voluntary  actions. 

The  actions  of  muscles  have  hitherto  only  been  considered  by 
physiologists  in  the  more  perfect  animals  where  this  (the  voluntary 
or  nervous  stimulus),  is  given,  which  becomes  a different  cause  of 
action  from  those  found  in  other  animals  and  vegetables. 

Those  actions  where  the  mind,  being  made  sensible  of  them,  may 
be  considered  as  a cause,  are  called  voluntary  actions;  and  those 
actions  over  which  the  mind  has  no  influence,  and  about  which  it 
is  not  in  the  least  consulted,  are  called  involuntary  actions.  The 
actions  of  the  muscles  which  go  on  without  the  influence  of  the 
mind,  but  can  be  restrained,  increased,  or  stopped  by  the  mind,  are 
called  mixed.  There  are  also  actions  which  may  be  allowed  to 
arise  from  a peculiarity  in  the  state  of  mind,  but  not  dependent  on 
the  will:  these  are  common  to  both  the  voluntary  and  involuntary 
muscles.  Thus  an  involuntary  muscle,  as  the  heart,  increases  its 
strokes,  and  the  voluntary  muscles  of  the  hands,  legs,  tongue,  &c., 
tremble  when  the  mind  is  agitated  by  anger,  fear,  &c.  These  four 
kinds  of  action  not  only  appear  to  arise  from  diflerent  causes,  but 
produce  different  phenomena. 

The  first  kind,  or  voluntary  motions,  last  only  for  stated  times, 
beyond  which  they  cannot  go,  the  muscles  either  losing  the  power 
altogether,  or  the  mind  becoming  incapable  of  stimulating  them  ; by 
which  means  a cessation  of  action  takes  place,  which  indeed  is 
necessary  for  the  preservation  of  the  animal.  For  these  actions, 
too  long  continued,  weaken,  hurt  or  destroy  the  body  ; and  there- 
fore the  mind  which  is  under  no  restriction  is  thus  prevented  from 
continuing  the  action.  We  have  this  beautifully  illustrated  in  some 
of  the’mixed  motions  : for  where  their  involuntary  motions  are  em- 
ployed for  the  preservation  of  the  animal,  as  in  breathing,  they  are 
constant ; and  where  the  stimulus  of  necessity  does  not  constantly 

* The  antherae  of  vegetables  requires  some  motion  to  make  them  burst ; some 
have  not  the  power  of  producing  this  motion,  but  if  the  power  is  given  theyburst 
immediately.  A blast  of  wind  is  often  necessary,  and  in  such  plants  propagation 
does  not  go  on  well  in  a calm  place. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


227 


take  place  they  rest,  as  in  the  stomach,  levator  palpebrarum,  &c. ; 
but  if  we  voluntarily  increase  the  actions  of  these  they  soon  tire. 

The  natural  involuntary  actions  of  muscles  are  such  as  never 
tire,  while  the  voluntary  always  do ; and  we  may  observe  that  the 
muscles  which  are  under  the  influence  of  both  are  never  tired  of 
their  involuntary  actions,  while  they  are  of  their  voluntary.  This 
we  might  suppose  was  owing  to  this  property  being  stamped  upon 
them  at  first,  and  for  very  wise  purposes ; but  it  rather  appears  to 
be  a property  arising  from  the  mode  of  impression,  viz.,  not  being 
impressed  by  the  will,  but  probably  acting  from  a general  impression 
in  the  machine,  viz.,  from  general  principles;  whereas  the  voluntary 
actions  are  caused  by  a peq,uliar  impression  of  the  will,  and  the  mus- 
cles are  so  constituted  as  to  tire  of  that  impression,  or  rather  be- 
come incapable  of  acting,  which  gives  the  sensation  called  tired. 
But  this  is  carried  further,  for  in  muscles  that  are  entirely  at  the  com- 
mand of  the  will,  if  they  take  on  involuntary  actions  they  never  tire. 

For  instance.  Lord  L ’s  hands  are  almost  perpetually  in  motion, 

and  he  never  feels  the  sensation  in  them  of  being  tired.  When  he 
is  asleep  his  hands,  &c.,  are  perfectly  at  rest ; but  when  he  w'akes, 
in  a little  time  they  begin  to  move. 

We  tire  of  voluntary  actions  whether  of  voluntary  parts  or  of 
parts  that  commonly  act  involuntarily,  as  the. muscles  of  respiration. 
Tiring  of  action  feels  to  the  mind  to  be  in  the  muscles  themselves, 
but  I imagine  it  must  be  in  the  mind,  although  it  is  referred  to  the 
muscles;  for  we  cannot  suppose  that  the  mode  of  action  of  a mus- 
cle directed  by  the  will  is  different  from  the  mode  of  action  when 
not  directed  by  the  will.  This  is  not  a tiring  of  the  will  itself,  but 
probably  a tiring  of  the  action  of  the  nerves  of  the  will ; and  as  the 
actions  of  these  nerves  is  always  referred  to  the  part  of  their  des- 
tination, the  tiring  is  also  referred  there.  • 

The  second  kind  are  the  involuntary  actions,  which  are  lasting, 
as  the  parts  themselves  : these  are  always  fit  for  action ; and  if  they 
are  inactive,  it  does  not  arise  from  the  want  of  power  in  the  part  to 
act,  but  from  a cessation  of  the  stimulus,  which. cessation  takes  place 
whenever  the  action,  from  peculiar  circumstances,  is  become  un- 
necessary. Such  actions  are  naturally  so  circumstanced  as  to  be 
constantly  wanted,  being  for  the  pres6rvation  of  the  animal,  as  the 
motion  of  the  heart. 

The  nerves  are  only  to  be  considered  as  conductors  carrying 
impressions  from  every  part  of  the  body  to  the  brain,  or  carrying 
the  command  of  the  will  to  those  muscles  whose  actions  can  only 
be  employed  about  such  external  objects  as  can  affect  the  mind  ; but 
those  parts  whose  actions  are  unknown  to  the  mind  appear  not  to 
be  affected  at  all  by  the  will. 

That  the  nerves  are  the  principal  agents  between  the  mind  and 
the  parts  would  appear  from  circumstances  respecting  their  com- 
parative size ; for  all  those  parts  which  convey  a strong  sensation, 
or  are  intended  to  perform  extraordinary  voluntary  actions,  have 
large  nerves;  while  those  parts  of  animals  which  neither  give  intel- 


228 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


ligence  to  the  mind  of  their  actions,  nor  are  under  the  influence  of 
the  mind,  have  very  small  nerves.  A stronger  instance  of  this  can- 
not be  given  than  the  electric  organ  of  the  torpedo,  where  the  power 
of  giving  or  restraining  the  shock  depends  upon  the  will : the  actions 
are  strong  and  violent,  for  he  can  soon  exhaust  himself  by  them ; 
and  the  nerves  which  convey  the  power  of  the  mind  exceed,  com- 
pared with  the  size  of  the  animal,  in  bulk  the  nerves  in  any  organ 
of  any  other  known  animal.  It  is  a part  whose  actions,  its  growth 
excepted,  depend  entirely  upon  the.will,  having  no  power  of  action 
of  its  own ; the  communication  between  the  will  and  the  organ  is 
large  in  the  same  manner  as  the  communication  between  the  senses 
in  general  and  the  brain  is  large. 

The  voluntary  muscles  have  large  nerves  to  command  the 
action  of  the  muscle,  which  is  independent  of  the  will,  although  in 
some  degree  subservient  to  it;  but  they  are  not  so  large  as  those 
of  the  senses  or  electric  organs,  where  they  give  the  part  its  whole 
action. 

A nerve  being  cut  going  to  a voluntary  muscle,  the  muscle  can- 
not obey  the  will,  and  thereby  loses  its  voluntary  actions;  but  it 
may  be  stimulated  into  action  by  immediate  impression  from  other 
causes,  as  electricity. 

The  voluntary  and  involuntary  muscles  having  their  quantity  of 
motion  in  an  inverted  proportion  to  their  quantity  of  nerves,  is  a 
strong  argument  against  the  nerves  being  the  cause  of  muscular 
motion. 

If  it  is  asked  why  the  involuntary  parts  have  nerves  at  all,  the 
answer  may  be  given  that  it  is  not  for  their  common  actions,  but 
to  keep  up  the  connexion  between  the  whole,  for  without  them  an 
animal  would  become  two  distinct  machines,-  and  one  might  be 
acting  very  contradictorily  to  the  other;  but  by  the  intercourse 
between  the  will  and  voluntary  parts,  between  the  voluntary  and 
involuntary,  and  also  between  these  last  and  the  mind,  an  universal 
and  uniform  agreement  or  regulation  is  kept  up,  which  communi- 
cation produces  one  kind  of  sympathy.  This  connexion  between 
the  living  principle  and  the  sensitive  produces  a compound  action, 
which  becomes  the  cause  of  the  instinctive  principle  in  animals. 

Muscles  are  either  employed  upon  the  internal  operations  of  the 
animal,  as  the  heart,  muscles  of  respiration,  stomach,  intestines,  &c., 
or  upon  external  matter  for  the  support  of  both,  as  those  of  the 
extremities. 

The  first  of  these  are  nearly  of  the  same  strength  in  the  robust 
strong  man  and  the  small  woman  or  man,  if  equally  healthy;  and 
it  is  right  it  should  be  so,  for  the  small  man  has  nearly  the  same 
resistance  to  cope  with ; but  it  is  the  others  which  constitute  the 
strong  or  weak  man. 

The  power  of  muscles  which  are  influenced  by  the  will,  although 
they  have  a common  power  of  action  with  those  independent  of  the 
will,  sooner  lose  their  powers  than  those  which  are  wholly  invo- 
luntary, as  the  heart,  stomach,  bladder,  blood-vessels,  &c.,  which 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


229 


would  seem  to  show  that  the  power  of  simple  life  lasts  after  the 
will  is  no  more. 

We  might  naturally  suppose  that  the  voluntary  muscles  have 
nearly  the  same  quantity  of  power  of  action  as  the  involuntary ; 
but  upon  considering  several  circumstances,  we  should  rather  con- 
ceive the  contrary  ; for  when  we  consider  the  power  by  which  the 
colon  of  a horse  propels  such  a load  of  solid  contents,  we  can 
hardly  conceive  the  power  of  any  voluntary  muscle  of  the  same 
thickness  equal  to  it.  For,  as  voluntary  motion  arises  from  two 
causes,  or  has  two  causes  of  action,  the  moment  one  of  these  ceases, 
the  power  which  remains  is  either  not  so  strong  originally  as  the- 
whole  power  of  the  involuntary  muscle  which  has  only  this  princi- 
ple of  action,  or  not  so  strong,  from  want  of  habit,  not  having  been 
always  employed  as  a principle  of  action  in  them. 

It  is  not  clear  to  me  but  that  every  muscle  has  a sphinctorial 
power  of  contraction  so  as  to  bring  them  to  the  middle  state.  This 
we  may  see  in  the  temporal  muscles ; for  by  opening  the  jaws  the 
muscle  sinks,  and  by  leaving  the  jaw  to  itself,  not  acting  with  it  in 
the  least,  the  jaw  rises  and  the  muscle  in  part  fills  up,  so  that  the 
jaw  is  suspended  by. the  half  action  of  the  muscle  ; how'ever,  this 
power  may  be  much  more  in  some  muscles  than  others. 

The  great  variety  of  causes  of  muscular  motion  make  it  almost 
inexplicable:  they  may  be  said  to  be  three, — the  will,  passions  of 
the  mind,  and  external  stimuli.  Those  actions  arising  fi'om  the 
will  and  the  mind  appear  to  be  most  simple,  because  they  are 
totally  unintelligible;  but  those  arising  from  external  stimuli  are 
either  voluntary  or  involuntary,  for  a muscle  that  acts  by  the  com- 
mand of  the  will  at  one  time  is  also  capable  of  being  thrown  into 
action  by  a particular  state  of  mind  or  external  stimulus. 

Those  actions  which  arise  from  the  will  have  reason  and  habit 
for  their  continuance  ; they  are  such  as  arise  out  of  imitation,  rea- 
soning, and  all  the  pow’ers  collected  by  the  senses. 

Those  actions  which  arise  from  the  mind  belong  mostly  to  the 
passions,  which  affect  more  muscles  of  the  body  than  the  will ; 
perhaps  there  is  not  a muscular  fibre  in  the  wdiole  animal  machine 
but  is  at  different  times  atfected  according  to  the  different  affections 
of  the  mind,  every  different  state  of  mind  having  its  particular 
muscles  to  stimulate. 

Upon  many  of-  these  occasions  reason  is  introduced,  which  is 
provided  by  this  state  of  mind  to  call  in  the  assistance  of  other 
muscles,  to  act  according  to  that  state,  either  to  bring  about  an 
increased  action  which  will  destroy  itself,  or  to  prevent  the  increase 
and  continuance  of  those  actions. 

From  extraneous  stimuli  arise  all  our  internal  insensible  actions, 
and  these  depend  upon  the  principle  of  simple  life,  upon  which 
depends  also  the  action  of  medicines ; and  health  is  only  the  right 
action  of  such  parts. 

Some  muscles  must  be  put  upon  the  stretch,  and  they  will  con- 
tinue their  action  far  beyond  the  easy  point,  or  that  which  was  so 

21 


230 


HUNTER  ON  THE  ANIMAL  ECONOMY. 


before  this  action,  as  the  stomach,  intestines,  and  bladder.  Others 
wait  to  be  stretched,  as  the  uterus ; this,  however,  is  not  the  cause 
of  its  contracting  again,  it  is  only  putting  it  in  a state  to  act  when 
another  cause  takes  place,  as  a miscarriage  or  foetus  at  the  full 
time.  This  is  neaidy  opposite  to  the  other,  for  what  endeavours  to 
empty  or  relax  the  uterus  becomes  the  cause  of  its  contraction, 
not  what  stretches  it. 

Voluntary  actions,  when  very  violent,  produce  involuntary,  as 
the  cramp,  from  dancing,  swimming,  &c. 

We  feel  every  involuntary  action  of  a voluntary  muscle,  while 
.we  do  not  feel  the  voluntary  actions ; nor  do  we  feel  the  actions  of 
an  involuntary  muscle.  When  such  actions  are  slight  we  only  feel 
them  as  little  convulsions,  contractions  in  different  parts  of  the  body, 
called  creeping  in  the  flesh,  or  quivering  in  the  eyelids  ; but  when 
these  become  violent,  as  in  cramps  or  spasms,  then  the  sensation  is 
pain. 

Voluntary  muscles,  the  stronger  they  are,  the  more  they  are  at 
the  command  of  the  will ; and  the  weaker  they  are  the  more  they 
seem  independent  of  the  power  of  the  will,  and  seem  to  be  either  at 
their  own  command,  or  at  that  of  the  nerve.  Strong  people  are  less 
subject  to  spasms  than  weak,  which  may  perhaps  arise  from  cus- 
tom ; the  strong  muscles  being  more  healthy,  are  oftener  in  use, 
and  thei’efore  become  more  at  the  command  of  the  will. 

Women,  childi’en,  and  sick  men  are  subject  to  fits,  for  the  reason 
just  mentioned  ; perhaps  also  diseases  of  the  uterus,  for  the  same 
reason,  are  the  cause  of  spasmodic  complaints,  it  being  very  little 
at  the  command  of  the  will,  but  of  other  circumstances  ; and  from 
this  disposition  draws  in  other  parts  by  consent,  and  so  brings  on 
general  spasm. 

Voluntary  muscles  always  become  tired  when  long  continued  in 
the  same  action,  which  accounts  for  animals  tiring-  sooner  by  being 
kept  in  one  position  than  if  allowed  to  move  ; and  we  find  a man 
can  hardly  stand  five  minutes  in  one  position  ; he  never  stands 
equally  upon  both  legs,  but  upon  one  as  a base,  the  other  as  a prop, 
so  as  to  be  able  to  shift  his  legs  as  they  tire. 

Animals,  also,  by  moving  or  producing  alternate  motions  by 
their  muscles,  can  go  on  for  a considerable  time,  but  their  alternate 
motion  must  not  be  quick,  as  it  always  requires  a certain  time  for 
muscles  to  regain  the  power  which  they  lost  in  action,  and  if  the 
alternate  motion  becomes  quick  and  violent,  it  may  tire  sooner  than 
constant  motion. 

The  voluntary  actions  of  young  animals  are  not  so  strong,  and 
are  much  less  lasting  than  those  of  middle  age ; that  strength  they 
have  they  are  not  capable  of  employing  for  any  great  continuance 
without  tiring,  especially  in  actions  where  a considerable  force  is 
required. 

Thus  we  have  young  horses  soon  fatigued  with  labour,  which 
the  same  horses  will  easily  perform  some  years  after.  This  ability 
in  the  older  horse  does  not  arise  entirely  from  a naturally  greater 
degree  of  strength,  joined  with  a natural  capability  of  continuance, 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


231 


but  in  some  degree  from  an  acquired  strength  from  employment, 
and  a capacity  of  endurance  from  the  habit  of  action.  This  might 
be  thought  sufficient  to  account  for  the  whole  difference, but  dealers 
in  horses  affirm  that  one  of  seven  and  one  of  four  years  old,  having 
equally  done  no  work,  shall  not  be  equal  in  their  continuance  of  it. 
In  riding  they  also  give  weight  according  to  age,  and  the  aged 
horse  always  carries  the  greatest  weight,  if  other  parts  are  equal.* 

When  an  animal  is  at  its  full  strength  is  not  easily  ascertained, 
but  it  cannot  be  while  growing ; it  must  have  arrived  at  its  full  ex- 
tent, and  perhaps  it  is  even  necessary  to  have  been  some  time  in 
that  state. 

The  involuntary  actions  are  stronger  before  this  period  than 
after ; this  is  perhaps  necessary  for  the  animal’s  growth. 

Besides  the  decrease  in  the  size  of  a muscle  from  an  atrophy, 
etc.,  and  the  restoration  of  them  again  to  their  natural  size,  which 
is  disease  and  health,  there  is  an  increase  which  accompanies  the 
whole  body,  till  it  arrives  at  its  full  size,  when  the  whole  seems  to 
rest,  except  the  muscles. 

How  long  the  muscles  continue  in  this  full  size  is  not  easily  ascer- 
tained, but  when  old  age  begins  to  come  on,  the  muscles  begin  to 
decay ; but  not  becoming  pale  and  flabby,  like  a diseased  muscle, 
but  retaining  their  redness  and  sound  appearance. 

A person  grows  thinner  after  a certain  age,  but  not  in  proportion 
to  the  decrease  of  size  of  the  muscles,  for  the  interstices  between 
the  bundles  of  fibres,  and  also  between  the  muscles  themselves,  are 
loaded  with  fat,  and  this  takes  place  so  constantly  that  an  old  man 
may  be  distinguished  from’  a young  one  from  only  seeing  the  mus- 
cles, and  the  fat  mixed  with  them. 

Muscles  in  old  people  lose  their  quantity  of  contraction,  and  the 
joints  are  therefore  never  moved  to  their  full  extent.  This  is  the 
loss  of  only  the  extreme  motion,  which  is  weak,  and  therefore  may 
be  supposed  to  arise  from  w'eakness  alone;  but  I do  not  think  this 
effect  is  produced  in  young  people  from  weakness. 

An  old  man  stands  with  his  knees,  thighs,  and  all  his  joints  bent, 
not  being  able  to  bring  himself  to  the  upright  position. 

The  actions  of  the  body  that  are  both  involuntary  and  voluntary- 
are  some  of  the  most  beautiful  circumstances  in  the  machine.  I 
believe  the  muscles  of  respiration  are  the  only  perfect  instances  of 
it.  The  sphincters  also  have  both  ; but  in  them  it  would  seem  to 
be  an  involuntary  continuation  of  an  action  which  is  voluntary. 

Fresh  air  was  necessary  for  our  existence,  and  it  was  therefore 
necessary  that  it  should  be  regulated  by  some  other  principle  than 
that  of  the  will ; for  it  is  necessary  when  we  sleep,  and  also  when 
W'e  will  the  contrary.  Therefore  our  will  has  its  limits  of  power 
over  the  involuntary  actions,  and  the  involuntary  also  have  their 
limits  over  the  actions  of  the  will ; each  therefore  can  only  go  a 
certain  length  in  opposition  to  the  other. 

As  all  animals  which  breathe  air  are  probably  endowed  with  the 

* How  accurate  these  gentlemen  are  I don’t  know. 


232 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


power  of  forming  sounds,  and  as  air  is  in  common  necessary  for 
such  an  effect,  Nature  has  made  this  air  answer  the  purpose  of 
sound  as  well  as  of  life.  For  the  purposes  of  life  it  was  necessary 
the  action  should  be  kept  pretty  regularly  constant,  and  therefore 
involuntary,  because  it  required  too  much  attention  of  the  will  to 
keep  up  the  necessary  action,  and  the  will  is  not  always  in  a state 
to  attend  to  it ; but  for  the  purposes  of  sound  it  was  necessary  it 
should  be  at  the  conimand  of  the  will,  for  sound  is  in  some  degree 
arbitrary  : for  although  often  attended  or  caused  by  a natural  pro- 
pensity at  the  time,  yet  it  can  be  avoided,  as  in  crying.  Vocal 
sounds^  however,  do  not  entirely  interfere  with  inspiration  and  ex- 
piration ; it  is  performed  by  the  last,  which  must  have  been  preceded 
by  the  first,  although  not  with  the  same  ease. 

Many  other  actions  of  the  body  interfere  with  involuntary  respi- 
ration ; all  violent  exertions  of  the  body  are  a check  upon  it ; but 
then  in  proportion  to  the  intended  exertion,  the  voluntary  supersedes 
the  involuntary,  and  they  take  in  a proportionate  quantity  of  air; 
but,  both  in  sounds  and  exercise,  if  continued,  the  stimulus  of  neces- 
sity for  a repetition  of  respiration  takes  place,  and  the  person  is 
obliged  to  take  in  a fresh  supply  of  air,  which  again  answers  the 
former  purpose. 


The  Colour  of  Muscles. 

Most  parts  of  an  animal  body  are  white,  and  when  they  have  any 
other  colour  it  generally  arises  from  some  adventitious  though 
necessary  matter,  as  the  pigment  of*  the  eye,  which  in  many 
persons  is  black,  in  some  green,  in  others  white,  &c. ; also  the 
pigment  of  the  skin,  w’hich  in  many  people  is  dusky  in  its  colour. 

A muscle  in  all  animals  is  in  itself  w'hite,  and  its  red  colour  found 
in  living  animals,  and  also  immediately  after  death,  arises  from  the 
blood  ; for  if  a red  muscle  be  steeped  in  water  it  will  become  white  ; 
or  if  the  arteries  of  a part  which  has  red  muscles  be  injected  with 
water  till  it  returns  by  the  veins,  the  muscles  soon  become  white. 
A red  muscle  exposed  to  the  air  loses  the  Modena  red,  becoming 
florid. 

As  the  colour  of  muscles  arises  from  the  blood  in  their  vessels, 
the  muscles  of  every  animal  must  have  the  same  colour  with  the 
blood;  if  the  blood  is  red,  the  muscle  will  be  more  or  less  so, 
according  to  its  quantity  ; for  in  sick  or  unhealthy  people  they  are 
pale. 

If  the  blood  is  of  any  other  colour  the  muscle  will  be  tinged  with 
that  colour,  and  also  in  proportion  to  the  quantity  of  the  blood. 

All  muscles,  hovv'ever,  have  not  the  colour  of  the  blood,  for 
many  animals  having  red  blood  have  their  muscles  almost  white; 
and  even  in  the  human  body  many  muscles  are  much  redder  than 
others.  The  muscles  of  an  arm  or  leg  are  much  redder  than 
those  of  the  stomach  or  intestines  ; those  of  the  face  are  much 
paler  than  the  temporal  or  masseter,  although  nearly  in  the  same 
situation. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


233 


The  muscles  of  quadrupeds  are  not  equally  red,  there  being  a 
great  difference  between  those  of  a hare  and  rabbit. 

The  difference  in  the  colour  of  muscles  in  the  same  animal,  and 
in  different  animals  of  the  same  order,  is  very  I’emarkable,  but  is 
equally  to  be  observed  in  another  order  of  animals,  viz.,  fowls. 

The  blood  in  fowls  is  red  ; there  are  few,  however,  in  which 
some  muscles  are  not  much  redder  than  others,  and  in  some  birds 
they  shall  be  almost  wholly  red,  as  in  the  black  cock,  while  in 
others  they  shall  be  nearly  all  pale,  as  in  the  turkey.  The  muscles 
of  birds  are  more  generally  pale  than  those  of  quadrupeds,  from 
their  having  a smaller  proportion  of  red  blood,  and  that  blood  being 
more  partially  distributed. 

The  muscles  in  frogs,  snakes,  tortoises,  &c.,  are  generally  pale, 
from  their  having  a still  smaller  quantity  of  red  blood,  and  that 
quantity  more  confined  to  the  vital  parts  than  in  birds. 

The  muscular  parts  in  fish  are  generally  white,  although  I believe 
they  have  all  red  blood,  but  in  smaller  quantity  than  even  frogs  and 
snakes,  so  that  the  motion  of  red  blood  in  them  is  much  confined  in 
its  extent,  appearing  to  go  no  further  than  those  parts  which  are 
essential  to  life. 

The  muscles  of  many  animals  of  a still  inferior  order  are  gener- 
ally pale;  the  blood  in  them  being  not  apparently  of  any  colour, 
and  in  some  almost  transparent,  as  in  the  lobster,  oyster,  snail,  &c.; 
and  in  this  order  of  animals,  if  the  blood  is  of  any  determined  colour, 
it  is  generally  so  confined  in  its  motion,  not  running  minutely  into 
parts,  that  they  are  hardly  tinged  with  it,  as  in  the  slug,  which  is 
black,  although  the  blood  is  of  a milk  white.  The  earth-worm, 
howmver,  is  an  exception  to  these  general  obseVvations  on  the  more 
imperfect  animals,  for  it  has  a great  deal  ofred  blood,  whjch  is  seen 
through  the  whole  body  of  the  animal,  from  the  external  covering 
being  pretty  transparent. 

The  I'ed  blood  in  a muscle  is  in  proportion  as  the  red  blood  in 
the  animal  is  to  the  quantity  of  muscle;  and  also  in  proportion  to 
the  quantity  of  action  in  the  muscle  and  the  quantity  of  red  blood 
taken  together. 

The  blood  in  the  more  perfect  class  of  animals,  as  man  and  qua- 
drupeds, and  in  which  class  whales  are  also  included,  is  in  greater 
quantity,  and  more  loaded  with  red  particles,  than  in  other  inferior 
orders;"^  therefore  the  muscles  are  in  general  redder,  and  the 
quantity  of  blood  in  this  order  of  animals,  and  perhaps  every  other 
order  in  which  they  have  red  blood,  is  rendered  greater  by  in- 
creasing the  action  of  the  muscles,  the  blood  being  driven  or  ex- 
tended further  into  those  parts  by  their  increased  action.  This 
happens  commonly  in  voluntary  muscles  only  ; the  involuntary, 

♦ [From  the  numerous  experiments  of  MM.  Prevost  and  Dumas  {Examtn  du 
Sang,  Bibl.  Uni.  de  Genev.,  t.  xvii.),  it  would  appear  that  the  red  globules  and 
fibrin  are  most  abundant  in  the  blood  of  birds,  in  which  respiration  is  most  active 
and  animal  temperature  highest.] 


21*= 


234 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


being  ennployed  in  uses  at  all  times  equal!}’-  necessary,  are  even  and 
constant  in  their  action. 

Muscles  much  at  rest  are  pale,  as  in  animals  just  come  into  the 
world,  before  the  muscles  have  had  much  action,  except  the  heart, 
which  has  been  acting  from  the  beginning ; and  all  the  muscles  of 
a young  animal,  except  the  diaphragm,  may  be  kept  pale  by  keep-, 
ing  the  animal  in  a state  of  rest,* * * §  for  in  that  state  the  blood  does  not 
pass  far  into  the  muscle;  but  as  the  animal  grows  up,  the  muscles 
become  redder  and  redder,  especially  if  they  are  allowed  action 
by  the  animal  taking  exercise,  and  nearly  in  proportion  to  that 
exercise. 

This,  however,  is  not  universally  the  case  ; for  the  natural  actions 
of  a hare  and  rabbit  are  not  very  different,  yet  the  muscles  of  a 
hare,  are  very  red,  and  those  of  a rabbit  pale ; whereas  I do  not 
believe  it  possible  by  rest  alone  to  make  a hare’s  pale,  although  by 
rest  they  will  become  proportionably  paler.f 

This  difference  in  animals  so  nearly  allied  would  seem  to  arise 
from  an  original  law  in  their  nature;  for  although  a hare  may  not 
have  a greater  quantity  of  motion  in  common,  yet  it  is  formed  to 
be  always  in  such  a state  as  if  it  really  had,  that  it  may  be  con- 
stantly prepared  to  undergo  such  motion.  The  rabbit  has  no  occa- 
sion for  such  a state  of  muscle,  its  sphere  of  action  being  much 
confined,  and  it  is  even  not  intended  to  run  fast. 

In  an  inferior  order  of  animals,  where  the  quantity  of  red  blood 
is  not  so  great;  and  the  destruction  of  voluntary  action  not  nearly 
equal  through  the  whole  muscular  mass,  we  find  a great  difference 
in  the  colour  of  muscles. 

A bird  has  two  kinds  of  progressive  motion,  flying  and  walk- 
ing. Some  principally  fly,  others  walk,J  and  many  perform  both 
equally. 

In  the  walking  bird  the  muscles  of  the  leg  are  the  reddest,  as  in 
the  pheasant,  partridge,  and  common  fowl.  In  the  flying  bird  the 
muscles  of  the  wing  are  the  reddest,  as  in  the  swallow  and 
woodcock. § 

In  the  frog,  snake,  turtle,  alligator,  &c.,  there  is  but  little  action, 
and  the  muscles  are  nearly  equally  employed  through  the  whole 
animal  except  the  heart;  so  that  there  is  not  that  difference  in  colour 
in  the  muscles  of  the  same  animal,  or  of  any  two  of  this  order, 
although  in  many  it  may  be  observable. 

In  fish  we  find  a good  deal  of  difference  in  the  colour  of  muscles, 
and  the  heart,  which  is  in  constant  action,  is  in  them  as  red  as  any 

* This  becomes  a distinguishing  mark  between  tlie  hares  of  a barren  mountain- 
ous country  and  a rich  flat  one. 

f Such  is  the  method  of  preserving  veal  white,  for  the  proportional  quantity  of 
red  blood  is  not  allowed  to  increase  or  go  far  from  the  heart. 

f Swimming  in  fowls  I consider  as  walking,  both  being  actions  of  the  legs. 

§ Epicures  are  sensible  of  this;  therefore  white  veal,  the  leg  of  woodcocks, 
are  delicious  bits,  and  the  feeders  of  domestic  fowls  indulge  them.  They  rob  the 
appetite,  however,  to  please  the  eye,  the  flavour  generally  being  in  the  muscles  of 
action. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


235 


other  animal.*  The  natural  history  of  fish  is  very  little  known, 
but  what  variety  there  is  we  may  attribute  to  the  cause  above 
.mentioned.f 

The  actions  of  the  more  inferior  orders  of  animals  we  shall  not  at 
present  enter  into. 

From  the  above  observations  we  may  conclude  that  red  blood, 
in  those  animals  that  have  it,  is  of  essential  use  to  muscular  con- 
traction. 

That  the  quantity  of  red  blood  brought  to  a muscle  is  of  service 
in  its  action  is  plain;  for  a muscle  become  paralytic  from  an  injury 
to  the  nerve,  or  an  anchylosis  in  the  joint  preventing  its  having  con- 
tracted for  many  years,  is  found  white,  small,  and  somewhat  liga- 
mentous, retaining  however  a degree  of  transparency  and  gelatinous 
consistence,  so  that  a muscle  may  become  paralytic  from  too  much 
rest  alone.  ^ 

The  wasting  of  a limb  which  is  seen  externally  takes  place  prin- 
cipally in  \he  muscles,  more  especially  where  they  are  paralytic 
from  an  anchylosed  joint ; in  that  case  the  muscles  alone  can  be 
supposed  to  be, affected,  they  alone  being  concerned  in  the  motion  ; 
but  where  it  arises  from  a defect  in  the  nervmus  system,  that  defect 
may  be  in  all  the  nerves  of  the  limb,  and  therefore  all  the  parts  may 
sufler  alike. 

Swelling  of  Muscles. 

We  may  suppose  that  the  blood  is  of  great  use  in  muscular  con- 
traction ; for  in  violent  and  frequent  actions  of  the  muscles  they 
swell  and  become  considerably  larger,  not  when  in  action  only,  but 
when  relaxed  immediately  after  the  action,  and  will  continue  swelled 
for  some  time. 

This  swelling  does  not  come  on  till  the  muscle  is  tired  of  acting; 
this  must  be  from  a gi’eater  influx  of  blood  at  that  time,  or  that  the 
action  does  not  let  the  blood  pass  so  freely  through  the  veins.  It 
must  be  owing  to  something  of  this  kind  w'hich  happens  to  animals 
which  use  much  violent  exercise,  and  are  killed  during  the  action, 
that  they  are  redder,  fuller,  and  eat  much  tenderer,  but  do  not  keep 
so  long.  There  is  a material  difference  between  a hare  or  deer 
that  is  shot  and  one  run  down  by  dogs. 

* [Most  of  the  above  facts,  with  ttieir  physiological  inferences,  vvere  known  to 
Grew,  who  alludes  to  them  in  the  following  digression  while  describing  the 
digestive  organs  of  the  bird:  “And  as  the  strong  and  continual  motion  of  all 
these  muscles  is  taught,  us  from  their  structure,  so  likewise  from  their  red  colour, 
which,  especially  in  the  grinders”  (the  lateral  muscles  of  the  gizzard,)  “ is  in- 
tense. Hence  in  a fish  the  muscles  which  move  the  fins  are  usually  red  although 
the  rest  of  the  flesh  is  very  white  ; and  so  the  leg  of  a domestic  fowl.  Whereas 
the  wings  also  of  a wild  fowl  are  of  the  same  colour.  So  likewise  the  flesh  of  a 
driven  calf,  or  of  a hare,  though  that  of  a coney  be  white.  And  that  which  comes 
nearer,  the  heart  in  all  creatures  having  the  like  continual  motion  is  of  a red 
colour.” — Anatomy  of  Stomachs  and  Guts,  fol.,  p.  41 ; 1681.] 

t [See  note,  p.  170.] 


236 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Muscles  not  only  become  really  larger  by  acting,  but  also  becorne 
larger  in  the  time  of  acting,  and  for  that  time  only,  subsiding 
gradually  after  the  action  is  over:  this  increase  is  in  proportion  to 
the  violence  of  the  action  at  the  time,  and  appears  to  go  on  till  they 
are  tired,  and  is  pi’obably  one  cause  of  their  being  so. 

In  order  to  ascertain  this  fact  as  much  as  possible,  I made  the 
following  experiments.  Immediately  after  getting  up  in  the  morn- 
ing, having  used  my  arm  as  little  as  possible,  I measured  the 
circumference  of  my  right  arm  across  the  belly  of  the  biceps 
flexor,  while  in  the  relaxed  state  of  all  the  muscles  of  this  part, 
and  found  it  measured  ten  inches  and  a half.  I then  bent  the 
fore  arm,  in  which  action  the  biceps  being  contracted,  I measured 
it  again  at  the  same  place,  and  found  it  twelve  inches  one-eighth, 
so  that  this  part  of  the  arm  had  gained  one  inch  and  five-eighths. 

After  having  thus  ascertained  the  size  of  the  arni,  both  w'hen  all 
the  muscles  were  relaxed,  and  also  wdien  contracted,  I next 
worked  an  air-pump  for  about  ten  minutes  with  considerable 
violence,  when  my  arm  became  quite  tired.  On  repeating  the 
above  mensurations  I found  my  arm  in  the  relaxed  state  eleven 
inches  and  five-eighths,  and  in  the  bent  state  twelve  inches  and  five- 
eighths  ; so  that  the  arm,  by  acting  ten  minutes,  had  acquired  an 
increase  of  six-eighths  of  an  inch  in  circumference  even  in  the 
relaxed  state  of  the  muscles,  and  four-eighths  in  the  contracted 
state. 

That  the  calf  of  the  lecj  swells  towards  nieht  is  a common  obser- 
vation ; and  I suppose  it  is  principally  owing  to  its  having  acted  so 
much  through  the  day. 

'That  the  swelling  in  such  cases  is  in  the  muscles  themselves  is 
evident  from  the  stiffness  felt  in  acting  with  tired  muscles. 

What  produces  this  temporary  increase  in  the  muscle?  It  is 
probable  that  an  extravasation  of  fluids  has  taken  place,  aiid  the 
weakness  induced  in  the  muscles  in  consequence  of  their  having 
acted  more  than  usual,  and  with  greater  force,  is  the  cause  of 
extravasation. 

Fleets  of  Habit  on  Muscles. 

Muscles  are  capable  of  being  improved  and  increased  in 
different  ways  by  exercise,  or  employing  the  muscle  much  in  its 
natural  functions. 

This  improvement  in  action  is  most  observable  in  the  muscles 
of  volition,  as  it  is  in  consequence  of  the  will  that  they  become 
more  familiar  with  the  actions;  and  also  they  are  more  subjected 
to  a variety  of  action,  sometimes  acting  strongly,  at  others  not 
at  ail. 

The  stimulus  of  the  will  never  loses  its  influence  by  habit  or  by 
becoming  familiar,  but  these  stimuli  may  be  called  arbitrary  or 
accidental,  foreign,  &c.  Muscles  not  only  improve  in  one  parti- 
cular, but  in  every  respect  whatever. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION.  237 

One  improvement  voluntary  muscles  acquire  from  Jiabit  is  the 
readiness  with  which  they  take  up  their  own  actions,  the  will  fre- 
quently only  having  to  set  them  a going ; there  are  instances  of 
people  playing  tunes  without  attending  to  the  notes  or  even  thinking 
of  the  tunes. 

• From  this  facility  of  obeying  the  will  in  beginning  actions,  and 
of  repeating  actions  they  have  been  accustomed  to,  with  the 
greatest  variety  of  motions,  in  the  voluntary  muscles,  particularly 
in  man,  and  also  from  the  frequent  employment  in  any  actions, 
muscles  acquire  a facility  in  obeying  the  mind  in  the  performance 
of  actions  they  had  never  tried  before,  going  hand  in  hand  with 
the  mind;  for  as  the  mind,  when  it  sets  the  body  to  perform 
actions,  acquires  a facility  in  immediately  employing  the  proper 
muscles,  they  obey  directly,  and  this  even  in  actions  they  never 
performed  before. 

A man  will  learn  one  trade  much  more  readily  if  he  knows 
another,  than  if  he  knew  no  trade  at  all. 

The  habit  of  acting  in  a muscle,  especially  when  employed  in 
considerable  exertions,  increases  the  necessity  of  becoming 
stronger,  which  necessity,  acting  as  a stimulus  upon  the  muscles, 
becomes  a real  cause  of  increase  of  size,  which  augments  their 
strength. 

This  effect  is  so  evident,  that  painters  and  sculptors,  as  well  as 
physiologists,  have  observed  it.  . We  have  Charon  and  Vulcan 
always  represented  with  large  shoulders,  brawny  arms,  and  their 
lower  extremities  small,  and  apparently  disproportloned. 

This  effect  is  still  more  nicely  marked  by  the  difi'erence  between 
the  right  arm  and  the  left ; the  right  being  generally  employed  in 
preference,  and  more  particularly  in  great  exertions,  is  therefore 
the  largest  and  strongest.  People  who  play  much  at  tennis,  where 
the  ball  is  always  struck  with  the  right  hand,  have  that  arm  much 
thicker  and  stronger  than  the  left ; therefore  a man  originally  well- 
proportioned  shall  lose  that  proportion  by  being  employed  in  any 
action  that  does  not  require  the  whole  body.  From  these  facts  it 
must  appear,  that  if  every  animal  was  perfectly  made,  with  respect 
to  any  standard  proportion  of  its  parts,  that  few  would  be  allowed 
to  grow  to  that  standard,  because  few  animals  exert  all  their 
muscles  equally,  there  being  in  most  some  circumstances  in  life 
which  oblige  them  to  exert  one  set  of  muscles  more  than  another. 
.This  is  probably  more  the  case  in  man  than  in  any  other  animal, 
and  also  in  him  less  determined  to  any  one  set  of  muscles  more 
than  another ; it,  however,  also  takes  place  in  animals,  as  there 
will  be  a considerable  difference  in  the  muscles  of  two  birds’ 
breasts  of  the  same  species,  one  being  allowed  to  fly,  and  the  other 
kept  in  a cage. 

The  increase  in  the  voluntary  muscles  appears  not  to  be  without 
limitation,  and  indeed  if  it  was  we  might  see  them  increase  beyond 
conception.  What  principle  sets  bounds  to  this  increase  from  ac- 
tion is  not  known ; the  circumstance  of  these  muscles  tiring  may 
become  a cause. 


238 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


This  increase  is  not  confined  to  the  voluntary  muscles,  for  the  in- 
voluntary, when  obliged  from  any  circumstance  to  act  with  un- 
common force,  also  enlarge,  and  become  stronger,  and  in  a much 
gre'ater  degree  than  the  voluntary. 

The  bladder  has  been  found  exceedingly  thickened  in  its  muscular 
coat  where  there  are  either  strictures  in  the  urethra  or  stones  in 
the  bladder,  for  in  this  last  complaint,  although  it  discharges  the 
urine,  yet  it  continues  to  act  with  more  violence  than  usual,  being 
irritated  by  the  stone,  which  it  cannot  expel.  I have  seen  it  in- 
creased to  three  times  its  natural  thickness.* 

Increase  of  thickness  in  the  auricles  and  ventricles  of  the  heart, 
in  consequejace  of  an  aneurism  in  the  arch  of  the  aorta,  is  not  un- 
common. 

The  cremaster  muscles  1 have  seen  very  much  enlarged  in  cases 
of  hydrocele  of  long  standing. 

In  the  increase  of  involuntary  muscles  there  appear  to  be  no 
limits:  the  power  of  increasing  seems  to  be  in  proportion  to  the 
necessity,  and  as  they  do  not  tire  there  is  no  end  to  their  power 
of  acting. 

Whether  this  increase  of  the  body  of  a muscle  is  a new  addition- 
of  muscular  fibres,  or  an  increase  in  size  of  those  already  formed, 
is  not  easily  determined,  but  I should  be  inclined  to  suppose  the  last. 


21.  CROONIAN  LECTURE  ON  MUSCULAR  MOTION,  NO.  II. 

[Read  before  the  Royal  Society  in  the  year  1797,  by  John  Hunter,  F.R.S.] 

THE  CONSTRUCTION  OF  THE  ANIMAL  MACHINE  WITH  THE 

3IECHANICAL  EFFECTS  PRODUCED  BY  THE  MUSCLES  AS  MECHA- 
NICAL POWERS. 

Mechanical  arrangement  of  the  Fibres  of  Muscles. 

The  most  simple  mode  of  investigating  an  animal  body  is  first  to 
consider  the  matter  of  which  it  is  composed.  In  this  inquiry  we 
shall  find  it  more  than  probable  that  there  is  but  one  species  of  mat- 
ter which  is  peculiar  to  animals,  and  therefore  I shall  call  it  animal 
matter. 

The  blood  appears  to  be  the  most  simple  modification  of  this 
matter : it  is  the  material  from  which  all  the  solids  are  composed. 

The  next  modification,  or  what  may  be  called  the  simplest 
organization,  is  a certain  arrangement  of  this  matter  so  as  to  pro- 
duce some  action.  This  may  be  of  two  kinds:  first,  such  an 
arrangement  as  may  take  place  in  any  kind  of  matter,  so  as  to 
produce  elasticity.  The  second  is  such  as  is  capable  of  producing 

* [Hunter  has  preserved  many  preparations  in  his  Pathological  Series  illustra- 
tive of  this  fact,  as  Nos.  746,  752,  755,  758,  759,  and  961,  &c.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION.  239 

a motion  in  itself,  without  the  cause  being  mechanical  as  in  elasti- 
city : this  is  the  composing  of  a muscular  fibre. 

A muscular  fibre  is  one  of  the  simplest  constructions  of  an  ac- 
tive solid,  and  it  is  these  fibres  which  compose  almost  the  whole  of 
many  animals. 

The  muscles  are  the  povrers  in  an  animal  body,  and  are  perhaps 
the  most  regular  parts  of  the  whole.  They  are  apparently  con- 
structed of  fibres  laid  nearly  parallel  to  one  another  ; in  some  they  are 
extended  longitudinally  from  one  end  to  the  other  of  the  muscle 
which  they  .compose;  in  others  their  direction  is  oblique  to  the  body 
of  the  muscle  ; this  obliquity  in  some  is  regular  from  one  end  of 
the  muscle  to  the  other,  while  in  other  muscles  the  fibres  lie  in  con- 
trary directions.  In  some  a number  of  these  oblique  portions  com- 
pose the  muscle ; the  parallelism,  however,  in  each  portion  is 
preserved.  This  parallelism  is  only  found  in  some  of  those  muscle 
whose  fibres  all  tend  to  one  point  of  action,  and  they  are  nearly  of 
equal  lengths  in  every  part  of  such  muscles;  but  where  parts  of  a 
muscle  produce  diflerent  effects  the  fibres  vary  in  length,  suited  to 
the  quantity  of  motion  admitted  by  the  directions  of  the  joints. 

The  most  simple  muscle  in  an  animal  body  is  a bundle  of  fibres, 
distinct  from  end  to  end  from  all  other  portions,  and  having  one 
determined  use.  The  muscles  which  m.ove  the  globe  of  the  eye 
come  the  nearest  to  the  idea  of  a distinct  muscle;  however,  there 
are  very  few  muscles  in  an  animal  body  so  unconnected  with  other 
muscles,  which  makes  it  difficult  in  many  cases  to  say  with  cer- 
tainty what  may  b’e  called  a distinct  muscle. 

If  we  take  a -view  of  what  v\ie  call  muscles  in  an  animal  body, 
the  human  for  instance,  we  shall  find  that  no  definition  can  be  given 
which  will  answer  to  them  all. 

A muscle  is  said  to  be  distinct  if  it  is  so  at  its  insertion  only, 
although  it  may  be  connected  with  others  at  ;ts  origin,  as  the 
extensor  indicis  proprius.  A muscle  is  distinct,  although  connected 
with  another  at  its  insertion,  if  there  is  a difference  in  the  use ; or 
although  connected  at  its  origin  with  one  muscle,  and  at  its  inser- 
tion with  another;  but  where  two  portions  of  flesh  are- united  at 
their  insertion,  both  having  the  same  use,  they  are  considered  as 
one  muscle.  So  that  it  is  the  particular  effect  which  is  produced 
by  a portion  or  portions  of  flesh  which  in  general  has  made  anato- 
mists either  unite  or  divide  them  into  separate  muscles. 

This,  however,  has  not  been  universally  followed ; for  in  some 
particular  muscles,  in  which  the  origin  is  of  considerable  extent, 
and  the  insertion  but  small,  each  part  of  the  muscle  having  the 
power  of  acting  separately,  and  producing  different  efiects  accord- 
ing to  the  parts  which  act,  (the  joint-  admitting  of  a variety  of 
motions,)  these  have  generally  been  considered  as  one  muscle  ; and 
in  such  muscles,  when  the  whole  acts,  it  produces  one  general 
effect,  as  in  the  pectoralis  major  muscle.  Also  those  muscles  in 
which  the  origin  and  insertion  are  of  considerable  extent,  and  pro- 
duce different  motions  of  the  same  part,  yet  produce  one  general 


240 


HUNTER  ON  THE  ANIMAL  CEUONOMY. 


effect  when  the  whole  acts,  are  considered  as  distinct  muscles,  as 
the  trapezius,  the  broad  muscles  of  the  abdomen,  &c.  When  a 
muscle  has  a number  of  insertions,  and  each  portion  moves  a dis- 
tinct joint,  while  the  whole  mass,  in  the  same  action,  moves  all 
these  joints,  it  is  thep  considered  as  only  one  muscle.  Of  this  kind 
is  the  longissimus  dorsi,  the  use  of  which  is  to  erect  the  whole  spine; 
but  its  particular  action  (if  it  had  any)  could  only  be  to  move  one 
or  more  joints,  according  to  the  number  of  portions  in  action. 

I 

External  Figure  of  Muscles. 

Muscles  have  various  shapes  and  sizes ; they  are  long,  short, 
thick,  round,  flat.  They  have  the  fibres  either  in  straight  lines  or 
in  curved  ones;  they  may  be  broad  and  thin,  or  hollowed  and  cir- 
cular, making  rings;  all  which  varieties  of  size  and  shape  are  con- 
nected with  their  action  and  use,  and  have  induced  anatomists  to 
give  them  different  nameS;  as  teres  major,  latisshnus  dorsi,  longus 
colli,  palmaris  brevis,  sphincter  oris,  '&c.,  rhomboidcs,  deltoides, 
pyramidalis,  &c.,  &c. 

The  form  and  size  of  muscles  are  adapted  to  the  uses  in  which 
they  are  employed  ; and  these  in  general  arise  from  the  nature  of 
the  parts  or  joints  to  be  moved. 

In  some  muscles  the  position  of  the  whole  leads  to  the  general 
direction  of  all  its  fibres  ; but  this  does  not  always  happen,  being 
the  case  only  in  muscles  of  a more  simple  construction.  A muscle, 
for  example,  lies  between  the  os  hyoides  and  the  upper  end  of  the 
sternum,  which  two  points  lying  nearly  in  the'  same  plane  would 
lead  one  to  presuppose  the  fibres  of  such  a muscle  to  be  rectilineal, 
which  is  really  the  case. 

• The  figure  of  the  muscle  often  shows  the  motion  of  the  joint 
which  it  moves,,  particularly  if  it  is  a simple  motion.  This  is  the 
case  in  the  rectilineal  muscles  and  those  which  are  nearly  so,  or 
those  which  are  radiated,  as  the  pectoralis,  diaphragm,  &c. 

The  different  lands  of  Muscles. 

Muscles  are  m.ore  or  less  complex,  arising  generally  from  the 
different  dispositions  of  their  fibres,  which  difference  is  owing  to  the 
manner  of  their  arising  and  being  inserted,  more  particularly  the 
former  ; and  hence  we  say,  muscles  are  straight,  broad,  radiated, 
half-penniform,  cbmplete-penniform,  and  complex. 

The  most  simple  muscle  would  be  one  whose  fibres  are  in  the 
direction  of  its  body,  or  in  a straight  line  between  the  two  resisting 
points,  and  should  be  called  rectilineal ; but  there  is  not  in  the 
human  body  a muscle  truly  rectilineal,  and  from  what  has  been 
observed  of  the  disposition  of  the  muscles  and  their  tendons,  also  of 
their  origins,  it  is  hardly  possible  to  have  one. 

The  straight  muscles  have  fewer  fibres  in  proportion  to  their 
size  than  the  oblique,  therefore  their  powers  are  less;  some  are 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


241 


rounds  or  nearly  so  ; others  are  flat  and  broad  : some  of  these  last 
are  radiated. 

The  half-penniform  muscle,  although  nearly  as  simple  as  any  in 
the  body,  appears  to  be  the  first  stage  towards  combination.  It  is 
composed  of  a series  of  fibres,  arising  from  a bone,  tendon,  or 
fascia,  but  more  commonly  a tendon,  of  which  the  insertion  runs 
nearly  parallel  to  the  origin,  representing  a quill  with  one  side  of 
the  feathers  taken  off.  This  disposition  of  fibres,  from  the  mode  of 
origin  or  general  disposition  of  the  bones  and  fascia  above  de- 
scribed, is  almost  as  common  as  any  in  the  body. 

The  complete-penniform  muscle  is  two  half-penniform  muscles 
joined  together. 

The  complex-muscle  is  several  complete-penniform  muscles 
united  into  one. 

There  are  many  half-penniform  and  complex  muscles  in  the  hu- 
man body,  but  hardly  one  instance  of  a distinct  complete-penniform 
muscle. 

In  proportion  to  their  combination  their  fibres  are  shorter,  and  a 
greater  number  in  a given  size,  which  must  make  them  proportion- 
ally stronger. 


Situation  of  Muscles. 

Muscles  which  move  bones,  cartilages,  &c.,  which  are  inflexible 
in  themselves,  generally  lie  upon  them ; for  instance,  the  biceps 
flexor  cubiti  lies  on  the  os  humeri,  the  latissimus  dorsi  upon  the  back. 
Now  the  humerus  and  spine  have  little  motion  in  themselves  when 
these  muscles  have  occasion  to  act.  Muscles,  how'ever,  lie  some- 
times upon  the  axis  of  motion,  the  body  of  the  muscle  going  over 
the  joint.  This  is  most  remarkable  in  parts  near  the  centre  of  the 
body,  as  in  the  muscles  of  the  spine,  and  in  those  of  the  first  joints, 
or  setting  on  of  the  extremities. 

The  necessity  of  this  disposition  will  appear  more  evident  when 
we  consider  the  vast  power  which  must  often  be  brought  into  a 
small  space.  In  the  spine,  for  example,  there  is  not  surface  sufficient 
in  this  chain  of  small  bones  for  the  origin  and  insertion  of  a sufficient 
quantity  of  muscle  ; therefore  the  fixed  point  of  the  most  superficial 
muscles  is  removed  to  a distant  and  broader  base,  and  they  pass 
over  several  joints  to  their  different  insertions,  as  the  longissimus 
dorsi,  sacro-lumbalis,  &c. 

The  same  disposition  is  necessary  in  the  first  joints  of  the  ex- 
tremities ; the  extremities  come  out  at  once  from  the  trunk,  which 
is  a broad  or  extended  base  for  muscular  attachment,  so  that  the 
muscles  are  obliged  to  pass  over  the  joint  some  wav  to  find  a sur- 
face for  their  insertion. 

Muscles  in  general  lie  in  the  direction  of  the  parts  they  are  to 
move;  there  are,  however,  exceptions  to  this  where  there  is  an 
irregularity  in  the  motion  of  the  joint,  as  in  the  motions  of  the  head, 
shoulders,  ribs,  thighs,  &c. 


22 


242 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


In  those  animals  which  have  one  great  centre  of  motion,  to  which 
series  of  smaller  ones  are  subordinate,  as  in  man,  the  bodies  of  the 
muscles  are  in  general  nearer  to  the  fixed  point  than  to  the  moving 
one ; and  the  muscular  fibres  often  arise  from  the  fixed  point  itself, 
without  the  interposition  of  a tendon ; these  muscles,  however,  do 
not  come  near  to  the  moveable  point,  but  are  attached  to  it  by  a 
tendon,  and  frequently  a very  long  one.  This  brings  the  body  of 
the  muscle,  which  is  the  heavy  part,  nearer  to  the  centre  or  basis 
of  the  whole  body,  which  is  most  able  to  support  it ; it  also  makes 
the  part  to  be  moved  freer,  more  fit  for  motion,  and  better  adapted 
for  other  purposes  which  may  be  required. 

Tendons  and  Fascice,  and  their  Uses. 

In  most  machines  constructed  for  motion  by  art,  there  is  the 
machine  itself,  or  all  the  diflerent  parts  which  are  formed  for  mo- 
tion, so  disposed  as  to  make  one  part  when  moved  become  the  cause 
of  motion  in  another,  communicating  it  to  every  partof  the  machine; 
and  the  moving  power  is  superadded,  and  is  not  to  be  considered 
as  being  a part  of  any  such  machine.  A horse,  for  instance,  cannot 
be  considered  as  a part  of  any  machine  which  he  moves,  although 
he  is  essential  to  its  motion. 

This  is  also  the  case  in  many  parts  of  the  more  perfect  animals 
where  great  variety  of  motion  was  necessary,  parts  being  con- 
structed for  the  purpose  of  motion  only,  having  no  power  within 
themselves,  but  this  power  is  superadded  or  applied  to  them,  as  in 
the  extremities  of  many  animals;  but  there  is  no  known  animal  so 
mechanically  constructed  in  all  its  parts  as  to  have  the  power  dis- 
tinct from  the  parts  to  be  acted  upon  in  every  part  of  its  structure. 
There  are  in  all  animals  parts  constructed  for  motion  which  have 
the  power  of  moving  within  themselves  ; those  in  the  more  perfect 
animals  are  the  heart,  stomach,  intestines,  &c.  In  the  more  simple 
animals  all  the  parts  of  the  body  are  composed  of  materials  with 
the  power  of  motion,  so  that  in  them  the  machine  and  power  are 
combined  in  one,  as  in  the  polypus,  leech,  worm,  &c. 

In  the  parts  of  the  compound  animal  constructed  for  motion  each 
part  is  independent  of  another,  so  that  one  part  may  move,  or  have 
its  motion  complete,  while  all  the  other  parts  are  at  rest ; hut 
although  the  mechanical  parts  are  so  constructed  as  to  have  their 
motions  independent,  yet  the  simple  effect  is  not  always  produced, 
for  the  powers  are  in  many  places  so  applied  as  for  one  power  to 
move  two,  three,  or  more  parts,  as  in  the  fingers.  The  same  powder 
has  often  a retrograde  eflect,  moving  the  part  which  was  its  fixed 
point  of  motion. 

In  an  animal  body  the  machine  constructed  for  motion  is  com- 
posed of  bones,  cartilages,  &c.,  and  the  unions  of  these  form  the 
places  for  motion,  called  joints. 

The  construction  of  the  bones  at  those  parts  which  constitute  the 
joints  is  only  such  as  adapts  them  for  motion  on  each  other,  not 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


243 


making  them  become  themselves  powers  so  as  to  move  each  other, 
as  in  the  machines  constructed  by  art. 

The  bones  and  cartilages  are  confined  or  kept  together  by  strong 
pliable  substances  called  ligaments. 

There  are  also  parts  called  tendons,  which  are  the  medium  of 
union  between  the  different  parts  of  the  machine  and  the  powers. 
They  have  hitherto  been  considered  as  belonging  to  the  powers ; 
but  I shall  rather  make  them  a part  of  the  machine  itself. 

A tendon  is  a peculiar  substance,  placed  between  some  muscles 
or  powers  and  the  parts  of  the  machine  to  be  acted  upon  by  such 
powers.  It  is  composed  of  white  fibres  placed  parallel  to  each  other, 
forming  a chord,  which  is  extremely  flexible,  has  no  sensible  elas- 
ticity, and  is  much  smaller  than  the  power  to  which  it  is  attached. 

Its  figure  is  in  general  a little  rounded  ; sometimes,  however, 
rather  flattened,  and  in  many  situations  it  is  broad  and  thin ; in 
all  cases  it  is  extended  between  the  body  to  be  moved  and  the 
power. 

It  is  sometimes  spread  out  in  breadth,  and  is  then  called  fascia: 
this  form  answers  various  purposes.  Its  fibres  in  some  situations 
run  pretty  parallel,  but  in  general  they  are  interwoven.  It  has 
flexibility,  strength,  and  convenience  in  size.  The  application  of 
this  substance  is  extremely  extensive,  complicated,  and  various. 

The  parts  adapted  to  motion  in  animal  bodies,  as  bones,  ten- 
dons, &c.,  are  formed  with  greater  nicety,  and  fitted  for  more  exact 
motions  in  the  more  perfect  animals,  of  which  we  have  a striking 
instance  in  the  human  subject. 

The  purposes  which  this  substance,  called  tendinous,  answers  in 
the  animal  machine,  are  the  following: 

First,  it  intervenes  between  the  body  to  be  moved  and  the  power, 
to  keep  up  the  exact  proportion  necessary  between  them  to  pro- 
duce any  determined  motions,  so  that  the  length  of  the  bones,  or 
the  distance  between  the  joints  or  points  of  motion,  the  quantity  of 
motion  in  the  joint,  and  the  quantity  of  contraction  in  the  muscle, 
are  proportioned  to  one  another.  But  if  this  substance  had  been 
wanting,  and  the  muscular  fibres  had  extended  the  whole  distance 
between  many  of  those  joints,  the  power  of  contraction  in  such  a 
muscle  would  have  been  much  too  great,  especially  in  the  ex- 
tremities.* The  tendon  is  used  for  this  purpose  principally  where 

* [A  most  beautiful  and  forcible  example  of  the  use  of  tendon  in  limiting  the 
length  of  a muscle  to  the  extent  of  motion  required  to  be  produced  in  the  part  to 
be  moved  occurs  in  the  "sterno-thyroidei  of  the  giraffe.  Had  these  muscles  been 
continued  fleshy  as  usual,  from  their  origin,  through  the  whole  length  of  the 
neck,  to  their  insertion,  it  is  obvious  that  a great  proportion  of  the  muscular  fibres 
would  have  been  useless,  because  such  a condition  of  the  muscle  would  have 
been  equal  to  have  drawn  down  the  larynx  and  os  hyoides  more  than  one  third 
of  the  extent  of  the  neck,  which  is  neither  required  nor  permitted  by  the  mechanical 
attachments  of  the  parts.  The  sterno  thyroidei,  therefore,  proceed  from  the  head 
of  the  sternum,  blended  together  in  one  fleshy  fasciculus  for  about  nine  inches,  and 
in  a tendon  which  is  continued  for  six  inches ; this  then  divides  and  the  muscles 
proceed  again  fleshy  for  about  sixteen  inches,  when  a second  tendon  intervenes 


244 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  fibres  of  the  muscle  run  parallel  to  the  direction  of  motion ; for 
we  shall  find  the  tendons  to  which  many  muscles  are  attached 
longer  than  we  could  suppose  necessary,  from  this  reason  singly. 
This,  how'ever,  arises  in  them  from  the  oblique  manner  in  which 
the  muscular  fibres  are  placed,  and  the  mode  of  their  being  attached 
to  the  tendon,  as  may  be  seen  in  the  complete-penniform. 

Secondly,  tendons  and  fascia  are  in  many  places  substituted  for 
bone,  there  not  being  a sufficient  surface  of  bone  for  the  attachment 
of  all  the  muscles  in  an  animal  body  ; and,  by  being  much  smaller 
and  thinner,  they  exclude  the  necessity  of  bone. 

Thirdly,  tendons  and  fasciae,  from  their  flexibility,  answer  in 
many  parts  better  than  bone;  for  if  a long  process  or  thin  lamella 
of  bone  had  united  the  ends  of  the  muscles  to  the  principal  bones 
to  be  moved,  no  motion  could  have  been  produced  by  the  endeavour 
of  such  muscles.  In  many  situations,  where  flexibility  is  not  re- 
quired, they  answer  better  than  bone,  from  their  yielding  to  external 
or  internal  pressure,  which  bone  could  not  have  done  without  being 
liable  to  be  broken ; as  in  those  situations  where  they  give  attach- 
ment to  two  muscles,  and  where  they  cover  many  muscles,  as  in 
the  forearm.  The  advantage  arising  from  the  flexibility  of  tendon 
and  fascia  is  seen  in  its  full  extent  by  comparing  the  muscles  of 
the  more  perfect  animals  with  those  of  the  oyster,  lobster,  or  turtle, 
where  many  of  them  are  attached  to  external  shells,  instead  of 
fasciae.  Flexibility  also  allows  them  to  vary  their  direction,  by 
which  means  they  vary  the  motion  of  the  parts,  as  in  the  tendon 
of  the  biceps  flexor  of  the  forearm  winding  round  the  head  of  the 
radius:  the  first  action  of  the  muscle  (in  some  positions  of  the  bone) 
gives  it  rotation  upon  its  axis,  the  second  bends  it  upon  the  os 
humeri.  Similar  actions  are  produced  by  the  latissimus  dorsi  and 
teres  major. 

Fourthly,  fascim  from  their  strength  answer  in  many  situations 
better  than  bone,  for  a lamella  of  bone  of  the  same  thickness  would 
in  many  cases  have  been  broken  by  the  conti-action  of  the  muscle 
to  which  it  was  attached. 

Fifthly,  it  was  necessary  that  some  substance  should  be  introduced 
as  a medium  between  bones  and  muscles,  to  admit  of  the  nicety  of 
action  and  freedom  of  motion  we  find  in  many  parts  of  the  body, 
particularly  in  the  fingers;  which  could  not  have  taken  place  if  the 
muscles  had  been  continued  from  bone  to  bone. 

Where  flexibility  is  not  necessary,  we  find  then  that  there  is  a 
continuation  of  bone,  as  in  many  birds,  as  in  the  leg  of  the  turkey, 

in  each  between  the  preceding  and  the  next  fleshy  portion,  which  is  finally  in- 
serted into  the  thyroid  cartilage,  and,  by  a continued  fascia,  into  the  os  hyoides  ; 
thus  the  quantity  of  contractile  fibre  is  proportioned  to  the  required  extent  of 
motion  by  intervening  tendons  ; the  sterno-hyoidei  being  wanting,  or  their  place 
supplied  by  the  sterno-thyroidci,  as  in  some  other  ruminants. 

The  analogue  of  the  omo-hyoideus  is,  in  the  same  animal,  adjusted  to  its  office 
by  a different  and  more  simple  modification  ; its  origin  is  removed  from  the 
shoulder-blade  to  the  nearest  point  (the  third  cervical  vertebra)  from  which  it 
could  act  with  the  requisite  force  and  extent  upon  the  os  hyoides.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


245 


partridge,  &c.,  and  thi'ough  the  whole  body  of  most  fishes  ; so  that 
tendon  is  to  be  considered  as  a substitute  for  bone  where  that  sub- 
stance would  be  improper.  Physiologists,  however,  have  given  a 
very  different  idea  of  it,  supposing  it  to  be  a continuation  and  con- 
densation of  the  muscular  fibres ; for  which  supposition  there  is 
no  proof,  even  the  smallest  shadow  of  reason,  either  from  analogy 
or  from  the  parts  themselves:  it  is  therefore  too  absurd  to  deserve 
refutation.  . 

Besides  the  uses  of  fasciae  above  described,  we  find  them  in  many 
parts  of  the  body  covering  muscles,  giving  origin  to  them,  binding 
down  the  belly  of  the  muscle,  and  also  binding  down  the  tendon 
which  is  attached  to  it:  this  application  of  them  is  chiefly  found  in 
the  extremities,  particularly  the  forearm  and  leg. 

Where  the  fascia  binds  down  the  tendon  at  or  near  the  joint  it  is 
called  ‘ annular  ligament,’  which  is  in  general  little  more  than  the 
fascia  made  strong  ; but  where  greater  nicety  in  the  motion  of  the 
parts  is  required  we  find  annular  bindings  independent  of  the  gen- 
eral fascia,  as  in  the  fingers  and  toes.  These  are  to  keep  the  ten- 
dons from  having  lateral  motions,  and  where  the  joint  makes  an 
angle,  to  prevent  their  coming  into  straight  lines,  which  would 
happen  if  not  prevented  by  this  annular  ligament,  and  which  would 
destroy  the  intention  of  the  joint,  as  is  evident  in  the  fingers. 

Where  the  fascia  covers  two  muscles  it  is  fixed  to  the  tendon 
which  lies  between  them,  and  generally  covers  their  tendons. 

Where  it  covers  a tendon  it  almost  surrounds  it,  making  a kind 
of  theca,  and  is  fixed  to  the  bone  along  which  the  tendon  passes. 

These  circumstances  only  take  place  where  muscles  are  placed 
at  a considerable  distance  from  the  parts  to  be  moved,  and  their 
tendons  pass  over  more  joints  than  one,  as  in  the  muscles  of  the 
forearm  and  leg,  where  the  tendons  go  to  the  fingers  and  toes. 

Fascia  is  sometimes  very  thin,  called  membrana  communis  mus- 
culorum, covering  superficial  muscles,  particularly  the  broad  ones, 
as  the  obliqui  extern!,  latissimus  dorsi,  pectoralis,  &c.,  and  on  some 
of  the  deeper-seated  broad  muscles,  but  thinner  and  looser  in  its 
connexion  with  the  muscles.  It.  is  never  met  with  in  this  state  on 
the  round  muscles. 

It  would  seem  to  be  intended  to  connect  the  skin  by  its  cellular 
membrane  more  closely  to  the  muscles,  by  which  means  the  skin 
may  be  in  some  measure  moved  by  them. 

The  fasciffi  in  some  instances  give  insertion  to  muscles,  as  in  the 
thigh,  and  to  the  broad  abdominal  muscles. 


Attachment  of  Muscles  to  Tendons. 

As  the  body  of  a muscle  is  much  thicker  than  the  tendon  to 
which  it  is  attached,  the  fibres  of  the  one  cannot  be  continued  to  the 
other  in  a straight  line;  therefore  the  end  of  the  tendon  is  not  joined 
to  that  of  the  muscle  in  one  line,  but  by  a tapering  point  or  an 
irregular  edge,  to  gain  surface  for  the  insertion  of  the  muscular 

22* 


246 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


fibres,  the  oblique  ending  of  a small  body  being  capable  of  becoming 
equal  to  the  less  oblique  ending  of  a thick  one;  but  the  direction 
of  the  tendon  cannot  be  the  same  with  the  muscular  fibres,  but  must 
be  more  or  less  oblique,  so  that  an  angle  must  be  formed  at  their 
union,  the  muscular  fibres  being  bent  a little  in  towards  the  tendinous 
ones.  This  obliquity  in  the  direction  of  most  of  the  muscular 
fibres,  and  of  their  attachments  at  both  ends  when  they  have  tendons 
at  both  origin  and  insertion,  makes  the  muscle  become  gradually 
thicker  from  the  body  of  the  first  tendon  to  the  most  distant  point 
of  that  tendon;  and  if  the  middle  part  of  the  muscle  is  free  from 
tendon,  that  part  will  be  everywhere  equal  in  size,  or  if  the  tendon 
at  its  insertion  goes  higher  than  at  its  origin,  the  part  where  these 
tendons  are  opposite  and  parallel  to  one  another  will  also  be  equal 
in  size,  the  body  of  the  muscle  from  that  part  becoming  gradually 
smaller  upwards  towards  its  origin,  and  downwards  towards  its 
insertion. 

From  such  disposition  of  fibres  the  bodies  of  most  muscles  are 
much  longer  than  their  component  fibres,  which  produces  in  the 
same  proportion  a shorter  complete  tendon.  This  circumstance 
lessens  the  thickness  of  the  bodies  of  such  muscles,  and  also  of 
their  extremities,  which  gives  to  the  muscle  a curve  in  its  outer 
line. 

The  obliquity  in  the  direction  of  the  muscular  fibres  admits  of 
there  being  a greater  number,  and  lengthens  the  swell  in  the  time 
of  contraction,  by  which  means  the  motion  of  the  muscles  in  the 
cellular  membrane  becomes  more  free,  the  swell  is  smaller,  and'the 
smoothness  of  the  whole  body  is  preserved.  The-  tendon  at  its 
origin  is  generally  on  one  side,  or  surrounding  the  muscle,  and  the 
inserting  tendon  is  on  the  opposite  side,  or  next  the  centre  of 
motion. 

Ongin  and  Insertion  of  Muscles. 

In  describing  the  origin  and  insertion  of  muscles  the  tendons  are 
always  included,  and  this  is  very  necessary  to  be  understood  of  the 
insertion,  as  it  is  the  point  of  insertion  which  in  some  degree  gives 
the  use  of  the  muscle.  ' 

The  origin  of  a muscle  is  in  general  the  most  fixed  point,  and  the 
insertion  the  point  where  the  greatest  motion  is  produced  ; in  differ- 
ent muscles,  however,  these  points  are  subject  to  variations,  and  on 
diflerent  occasions  in  the  same  muscle,  most  of  them  being  capable 
of  acting  from  either  end.  Some  of  these  variations  may  be  consi- 
dered as  natural,  and  others  as  a force  upon  Nature. 

I shall  call  the  variations  natural  where  the  effect  is  necessary  in 
the  natural  movements  of  any  part  of  the  body,  such  as  the  exten- 
sors of  the  thigh,  the  glutrei,  particularly  the  glutasus  major,  are 
commonly  understood  to  produce  ; for  these  muscles,  in  the  action 
of  walking,  when  the  leg  is  brought  forwards  or  bent  by  the  flexors, 
extend  the  body  upon  the  thigh,  by  which  action  the  body  is  brought 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


247 


forwards  before  and  over  the  foot ; also,  after  stooping  or  bending 
the  body  forwards,  the  glutreus  muscle  raises  it ; and  these  are  as 
much  the  actions  of  this  muscle  as  bringing  the  leg  and  thigh  back 
upon  the  body. 

Some  n)uscles  are  capable  of  performing  similar  inverted  actions, 
although  not  commonly  so  employed  as  the  recti  abdominis,  whose 
ordinary  use  is  to  bend  the  body  upon  the  pelvis,  but  which  some- 
times, however,  bend  the  pelvis  upon  the  body.  Those  which  I call 
a force  upon  the  natural  etfect  of  the  muscle,  or  an  inversion  of  the 
fixed  point,  are  where  the  moving  point  is  by  art,  or  something  foreign 
to  the  body  made  the  fixed  one,  as  the  hand  ; and  the  action  of  the 
muscles,  instead  of  bringing  the  hand  to  the  body,  draw’s  the  body 
to  the  hand. 

In  many  animals,  however,  the  effects  of  certain  muscles  are  re- 
ciprocal, and  these,  therefore,  cannot  be  said  to  have  an  origin  and 
insertion,  both  the  parts  to  which  they  are  attached  being  equally 
moveable  in  themselves,  and  there  being  no  power  capable  of  keep- 
ing either  the  one  or  the  other  firm,  as  is  very  evident  in  animals 
where  the  two  points  of  attachment,  or  parts  to  be  moved,  are  similar 
or  in  pairs,  as  in  the  bivalve  shell,  where  the  motion  in  the  two  valves 
is  equal. 

The  origins  of  muscles  are  in  general  more  simple  than  their  in- 
sertions, nothing  being  w'anted  but  a sufficient  surface  for  attach- 
ment, which  is  generally  required  to  be  pretty  extensive  ; and  for 
this  purpose  there  are  various  contrivances,  which  have  given  rise 
to  particular  names,  for  the  various  kinds  of  origins. 

The  origin  of  a muscle  is  generally  from  an  immoveable  part 
with  respect  to  the  action  of  that  muscle,  and  commonly  from  the 
most  firm  or  solid  parts  of  the  body,  as  bones,  cartilages,  periosteum, 
tendons,  and  fascia;  some  muscles,  however,  arise  from  soft  parts, 
as  the  lingualis,  orbicularis  oris,  &c. 

The  insertions  of  muscles  are  less  simple,  for  as  the  insertion  is 
to  produce  the  various  motions  of  the  parts,  and,  as  the  construc- 
tion for  motion  is  hardly  the  same  in  any  two  joints,  more  nicety 
and  art  is  required;  the  insertions  of  muscles  are  cornmonly  more 
determined  than  the  origins. 

Few  muscles  are  so  situated  as  to  arise  from  surfaces  at  right 
angles  to  the  direction  of  their  fibres,  as  they  generally  pass  nearly 
in  the  same  direction  with  the  surface  from  which  they  arise,  whe- 
ther bone,  tendon,  or  fascia.  They,  therefore,  take  their  origin 
from  a part  as  they  pass  along  it,  which  renders  it  very  oblique, 
and  produces  the  form  of  muscle  called  half-penniform.  Some 
muscles,  however,  both  arise  from,  and  are  inserted  into,  surfaces 
at  right  angles  to  the  direction  of  their  fibres,  as  many  of  the 
spine,  &c. 

The  insertions  of  muscles  are  more  general  than  their  origins, 
for  they  must  be  inserted  into  every  part  of  the -body  to  be  moved, 
and  therefore  we  find  them  inserted  into  bones,  cartilages,  periosteum, 
tendons,  fascia,  and  many  of  them  into  soft  parts,  as  the  skin,  cel- 
lular membrane,  the  tongue,  &c. 


248 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


In  describing  muscles,  they  are  never  said  to  be  inserted  into,  or 
to  arise  from,  periosteum,  but  from  the  bone  the  periosteum  covers, 
as  it  is  upon  the  bone  the  effect  is  produced. 

Muscles  never  arise  from,  or  are  inserted  into,  capsular  ligaments, 
for  although  in  some  few  cases  they  seem  to  run  into,  or  are  at- 
tached to  them,  the  effect  is  not  immediately  on  the  capsular  liga- 
ment, but  on  the  bone  beyond  it,  and  the  ligament  is  strengthened 
at  this  part  in  proportion  to  the  power  of  the  muscle;  so  that  in 
this  case,  as  far  as  regards  the  mechanical  effect,  the  ligament  and 
tendon  may  be  considered  as  one. 

Many  tendons,  in  their  course  over  joints,  adhere  to  the  liga- 
ments, and  bring  them  along  with  them  in  the  action  of  their  muscles. 
This  adhesion,  however,  is  only  to  bring  out  a secondary  use,  to 
save  the  ligament  from  being  bruised  between  the  bones,  which 
otherwise  might  have  been  the  case. 

Many  muscles  besides  these  insertions  give  off  fibres  to  the  fasciae, 
wdiich  cover  other  muscles,  as  is  evident  from  the  lower  edge  of  the 
pectoralis  major,  biceps  flexor  cubiti,  semitendinosus,  &c.,  but  what 
is  intended  by  it  is  difficult  to  determine. 

The  origins  of  muscles  are  generally  further  from  the  centre  of 
motion  of  the  part  to  be  moved  than  the  insertion ; remarkable  in- 
stances of  this  are  seen  in  the  biceps  flexor  and  triceps  extensor  of 
the  forearm,  and  all  the  movers  of  the  hand  and  fingers.  This 
gives  neatness  to  the  parts  to  be  moved  ; but  its  principal  use  is  to 
give  velocity  to  the  motion,  with  a small  quantity  of  contraction; 
what  it  gains,  however,  in  velocity,  it  loses  in  strength.  That 
velocity  is  the  intention  is  evident,  for  if  the  muscular  fibres  had 
been  continued  to  the  most  distant  end  of  the  bone  to  be  moved, 
the  muscle  must  have  been  longer,  and  must  have  contracted  more, 
to  produce  the  same  effect,  which  contraction  must  have  taken  a 
greater  length  of  time.* 

Many  muscles  arise  near  to  the  centre  of  motion  of  the  part  to 
be  moved,  and  are  inserted  at  a considerable  distance,  as  the  del- 
toides.  This  also  produces  a great  deal  of  motion  in  the  part  to  be 
moved,  with  very  little  contraction  of  the  muscle ; for  when  the 
greatest  quantity  of  motion  is  produced,  the  insertion  has  approached 
very  little  nearer  the  origin. 

This  kind  of  insertion  gives  an  advantage  to  the  power  of  the 
muscle,  which  the  other  has  not,  viz.,  a much  longer  lever,  and 
allows  the  muscles  to  communicate  their  strength  to  the  moving 
parts  more  fully,  although  with  less  velocity;  and  being  employed 
upon  parts  of  considerable  extent,  as  the  arm  and  leg,  and  gener- 
ally upon  the  first  joints  of  thetfi,  the  effects  upon  the  hand  and  foot 
are  very  considerable. 

In  the  formation  of  many  parts  of  the  body  neatness  is  a prin- 
cipal object,  as  is  visible,  not  only  in  the  external  form  of  the  limb, 
but  in  the  parts  constructed  for  motion  ; as  in  the  formation  of  the 

* [The  extent  of  the  space  through  v/hich  the  hone  is  moved  is  also  greatly 
increased  by  this  arrangement,  in  comparison  with  the  extent  to  which  the  muscle 
itself  contracts.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


249 


bones,  and  their  situation  with  respect  to  one  another,  and  the  mode 
of  removing  the  inserted  tendon  (when  too  close  to  the  centre  of 
motion  to  produce  a sufficient  effect)  a little  further  off,  by  means 
of  little  moveable  bones  called  patellae  or  sesamoid  bones,  as  in  the 
knee,  first  I'oints  of  the  thumb,  and  great  toe : and  where  this  con- 
struction w'ould  be  clumsy  and  inconvenient,  as  in  the  fingers  and 
lesser  toes,  the  two  tendons  which  are  obliged  to  pass  along  these 
parts  to  their  insertions  at  the  second  and  third  joints,  are  so  dis- 
posed in  their  course,  that  the  profundus,  or  one  nearest  to  the  bone, 
acts  as  a patella  to  the  other,  keeping  it  at  a distance  from  the 
centre  of  motion  equal  to  its  own  thickness;  and  the  subliinis  or 
upper  one  is  obliged  to  split  into  two  near  its  termination  before  it 
can  be  inserted  into  the  second  bone.  The  advantage  gained  by 
this  construction  is,  that  the  tendon  of  the  muscle  employed  in  the 
greatest  action  is  removed  further  from  the  centre  of  motion  than 
it  otherwise  could  be,  and  from  which  the  other  sustains  no  disad- 
vantage. 

Adaptation  of  Muscles  to  Joints. 

It  is  to  be  understood  that  the  joints  of  an  animal  are  fitted  for 
motion,  and  that  their  form,  with  the  application  of  the  muscle  or 
power,  are,  in  a natural  state,  so  adapted  to  each  other  that  the 
power  acts  with  the  greatest  advantage,  and  that  any  variation 
from  the  natural  form  or  position  of  the  joint  weakens  the  effect  of 
the  power.  This  may  be  demonstrated  in  those  who  turn  out  their 
toes,  as  in  a dancing-master,  who,  before  he  makes  a leap,  turns 
his  toes  forwards. 

Few  joints  in  an  animal  body  are  confined  to  one  motion,  there- 
fore either  a number  of  single  muscles  must  be  employed,  or  the 
direction  of  the  muscular  fibres,  of  the  tendons,  and  of  the  inser- 
tions, must  be  so  disposed  that  a few  muscles  may  produce  the 
different  effects. 

Joints  admitting  of  motion  in  only  one  direction  come  nearest  to 
a simple  joint : the  joint  of  the  elbow  is  perhaps  as  near  this  as  any 
in  most  animals,  as  also  the  joint  of  the  lower  jaw  in  the  car- 
nivorous animals,  and  the  fingers  in  most  animals:*  the  muscles  of 
such  joints  are  tolerably  simple  in  their  structure,  direction,  and 
insertion: 

In  the  joints  W'hich  admit  of  various  or  compound  motions,  the 
construction  of  the  muscle,  the  course  of  its  different  fibres,  the  dis- 
position of  the  tendon  in  its  course  and  insertion,  produce  a great 
variety  of  effects. 

This,  indeed,  was  absolutely  necessary  in  a number  of  animals, 
more  especially  those  which  have  extremities,  and  particularly  the 
human  subject,  in  which  there  are  more  motions  produced  than 
separate  muscles  to  perform  them ; nor  was  it  possible,  in  the  pre- 
sent construction  of  bones,  &c.,  to  have  placed  particular  muscles 

* [In  insects  and  Crustacea  every  joint  of  the  extremities,  save  that  which 
is  between  the  limb  and  the  body,  is  ginglymoid,  and  limited  to  motion  in  one 
plane.] 


250 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


so  as  to  perform  all  the  motions,  without  interfering  in  the  opposite 
actions.  In  the  human  subject  the  number  of  muscles  exceeds  that 
of  any  other  animal ; the  motions  in  the  joints,  however,  are  still 
greater  than  can  be  accounted  for  by  the  increase  in  number  of 
muscles,  tiie  difference  in  the  construction  of  the  muscles,  as  well 
as  of  the  joints,  producing  this  difl’erence,  which  is  so  remarkable 
in  the  joint  of  the  shoulder,  the  rotatory  motion  in  the  forearm,  and 
the  joint  of  the  thigh. 

Instances  of  the  different  motions  produced  by  the  shape  of 
muscles,  their  mode  of  application,  and  the  disposal  of  tendons,  are 
seen  in  the  biceps  flexor  cubiti,  latissimus  dorsi,  &c.,  passing  some 
way  round  the  bones  into  which  they  are  inserted,  so  as  to  produce 
two  very  different  motions  in  the  parts;  at  one  time  they  may 
move  the  part  through  some  space,  at  another  time  upon  its  own 
axis.  The  muscles  in  the  lower  jaw  in  graminivorous  animals 
give  a remarkable  instance  of  this,  there  being  hardly  any  of  them 
W'hich  do  not  perform  more  than  one  motion. 

The  disposition  of  tendons  will  often  give  a different  direction  to 
the  body  moved  from  that  of  the  muscle,  arising  from  the  tendon 
bending  over  some  fixed  point  and  taking  another  direction,  which 
is  beautifully  illustrated  in  the  trochlearis  muscle  of  the  eye,  the 
body  of  it  passing  in  the  same  direction  as  the  straight  muscle  of 
the  eyeball,  while  from  the  course  of  its  tendon  it  counteracts  the 
oblique,  which  passes  in  a different  direction.  The  obturator 
internus  of  the  thigh  and  circumflexus  palati  are  both  of  this  kind. 

The  different  positions  of  tendons  shall  make  two  muscles  pro- 
duce the  same  effect  in  different  ways,  being  inserted  in  the  opposite 
sides  of  the  same  joint.  The  gastrocnemius,  w'hich  is  inserted  into 
the  heel  behind  the  joint  of  the  foot,  pulls  the  heel  up,  which  de- 
presses the  toes.  The  tibialis  posticus  and  peronei  muscles,  which 
pass  in  the  same  direction,  and  are  inserted  before  the  joint  of  the 
foot  by  means  of  their  tendon  passing  round  the  joint,  also  pull  the 
toes  down,  w hich  raises  the  heel. 

Muscles,  by  the  course  and  mode  of  insertion  of  their  tendons, 
shall  perform  very  differently  a series  of  regular  motions,  bending 
some  joints  and  extending  others.  Such  are  the  uses  of  the  lumbri- 
cales  and  interossei  interni  upon  the  fingers  and  toes:  for  their 
course  is  before  the  centre  of  motion  in  the  first  joint,  but  by  wind- 
ing round  the  second  hone  they  get  upon  the  back  of  the  fingers 
and  extend  the  two  last  joints.  These,  by  their  situation  and  inser- 
tion, produce  an  effect  which  could  not  be  performed  by  the  other 
flexors  or  extensors  of  the  same  parts. 

From  the  various  formations  of  joints,  and  the  different  positions 
and  insertions  of  the  muscles  or  powers,  the  greatest  force  of  the 
power  is  required  at  different  periods  of  the  motion. 

In  all  those  where  the  power  is  between  the  centre  of  motion  and 
the  resistance,  the  greatest  action  of  the  muscle  is  required  at  the 
beginning,  as  a smaller  contraction  of  the  muscle  produces  a greater 
effect  at  this  time  than  afterwards,  as  in  the  deltoid. 

Where  the  power  and  weight  are  at  the  two  ends  and  the  fulcrum 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


251 


in  the  middle,  as  in  the  biceps  extensor  of  the  arm,  or  where  the 
power  and  the  fulcrum  are  at  the  two  ends  and  the  weight  in  the 
middle,  as  in  the  muscles  of  the  tendo  Achillis,  the  greatest  force  is 
required  in  the  last  part  of  the  motion. 

VVhere  there  is  no  lever,  but  one  body  moving  round  a centre  as 
a pulley,  which  is  the  case  in  the  extensors  ot  the  knee-joint,  the 
same  force  is  required  through  the  whole  of  the  motion. 

We  may  observe  that  the  ligaments  of  the  joints  are  necessarily 
so  constructed  and  placed  with  respect  to  their  motion  as  to  produce 
an  effect  analogous  to  that  of  a centre-pin  in  a plain  circular  joint, 
in  all  the  various  situations  of  the  centre  of  motion. 

There  are  few  levers  of  the  first  kind  in  the  body,  on  account  of 
the  unevenness  in  the  effects  of  muscular  contraction  upon  them, 
arising  from  the  variation  taking  place  in  the  angle  of  insertion  of 
the  muscle;  they  are  therefore  introduced  where  that  is  compen- 
sated by  some  other  circumstance  in  the  action. 

The  motion  of  the  body  upon  the  thigh  is  a lever  of  this  kind,  and 
is  generally  used  in  raising  the  body;  but  as  the  body  becomes 
more  and  more  bent  it  requires  less  power  to  overcome  the  power 
of  gravity  in  the  body,  therefore  the  angle  of  insertion  is  becoming 
more  and  more  in  the  same  plane  with  the  moving  part.  The  same 
thing  takes  place  in  moving  the  heel. 

The  angle  of  insertion  can  only  have  its  effects  vary  when  the 
insertion  is  some  way  from  the  centre  of  motion,  and  this  only 
when  in  levmrs. 

When  in  levers  of  the  first  kind  (which  extend  joints)  the  effect 
is  gradually  becoming  less;  as,  for  instance,  the  extensors  of  the 
forearm,  which  are  inserted  into  the  olecranon,  because  the  angle 
is  becoming  less  and  less;  but  perhaps  the  velocity  which  the  parts 
m.ay  commonly  acquire  make  up  this  loss.  When  inserted  into 
levers  of  the  second  kind  they  are  gaining  in  their  effect,  the  angle 
becoming  greater,  as  in  the  flexors  of  the  forearm. 

In  the  lever  of  the  first  kind  the  quantity  of  effect,  according  to 
the  quantity  of  contraction,  is  becoming  more  and  more  as  the  angle 
becomes  less.  In  the  second  it  is  becoming  less  and  less  as  the 
angle  becomes  greater. 

Muscles  going  over  more  Joints  than  one. 

Many  muscles,  or  their  tendons,  go  over  two  joints  while  they 
only  move  one,  and  the  joint  which  they  do  not  move  is  often 
moving  in  a contrary  direction,  from  the  action  of  another  muscle; 
this  happens  in  the  biceps  flexor  and  extensor  of  the  forearm,  the 
flexors  of  the  leg,  &c.  This  disposition  saves  a great  deal  of  mus- 
cular contraction ; for  by  the  biceps  going  over  two  joints  while  it 
is  employed  in  bending  the  forearm  upon  the  arm,  the  arm  is  bend- 
ing back  upon  the  scapula,  which  last  action  would  produce  in  some 
degree  a flexion  of  the  forearm,  even  if  the  biceps  flexor  did  not 
contract  at  all,  but  only  remained  without  relaxing.  This  arises 
from  the  mofion  of  these  joints  going  zigzag  to  one  another. 

Muscles  whose  tendons  pass  over  two  joints  keep  the  joint  not  t 


252 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


be  moved,  firm;  which  is  of  great  service,  as  when  we  bend  the 
forearm  by  the  biceps  flexor,  the  two  heads  rising  from  the  scapula, 
especially  the  long  head  which  runs  through  the  joint,  keeps  the 
joint  of  the  shoulder  firm.  In  this  motion  there  are  muscles  acting 
on  both  sides  of  the  joint.  Had  it  not  been  for  this  purpose,  the 
biceps  flexor  might  as  well  have  arisen  from  the  head  of  the  os 
humeri. 

Muscles  often  go  over  two,  three,  or  four  joints,  and  only  move 
the  third  and  fourth,  as  the  flexors  of  the  last  joints  of  the  fingers  ; 
but  to  prevent  the  first  and  second  joints  being  moved  by  this  action, 
the  extensors  of  the  intermediate  joints  are  obliged  to  interfere  and 
keep  them  from  bending. 

Every  joint  has  a certain  quantity  of  motion,  and  the  quantity  of 
contraction  of  the  muscles  of  that  joint  are  adapted  to  that  motion  : 
we  have  therefore  in  joints  of  considerable  motion  long  muscles,  as 
those  of  the  knee,  and  in  joints  with  little  motion  we  have  short 
muscles,  as  those  of  the  spine. 

Of  the  Strength  of  the  Body  as  compounded. 

The  strength  of  a part  and  the  strength  of  the  whole  body  is  in 
proportion  to  tlie  natural  resistance,  which  arises  either  from  some 
body  to  be  propelled,  as  the  blood,  urine,  &c.,  or  from  the  position 
of  our  bodies,  to  overcome  gravitation;  for  every  muscle  in  the 
body  is  just  able  to  move  the  part  to  which  it  is  fixed  with  tolera- 
ble ease  in  the  most  diflicult  position,  and  any  additional  weight  in 
that  position  will  fatigue  it,  it  being  unable  to  support  it  any  time. 
From  this  it  would  appear  that  the  diflerent  parts  of  our  bodies  are 
not  much  stronger  than  can  support  their  own  motions  with  ease; 
and  whatever  motion  the  body  can  perform  with  ease,  by  exerting 
itself  it  can  give  it  a considerable  velocity,  or  support  a greater 
weight  for  a continuance. 

If  our  muscles  are  capable  of  moving  our  bodies  in  every  position, 
they  must  be  able  to  move  much  more  in  some  positions  than  others. 
If  I can  raise  my  body  from  the  ground  perpendicularly  up  when 
my  feet  are  fixed  upon  the  ground  and  my  knees  bent  at  right 
angles,  I can  support  or  raise  a much  greater  w’eight  when  upright 
or  nearly  so. 

If  a horse  raise  himself  from  the  ground  when  his  legs  are  bent, 
he  can  support  a greater  weight  when  erector  standing;  and  if 
loaded  with  no  more  than  he  can  stand  under  upon  three  feet,  he 
can  walk  with  it.  A leg  also  that  can  raise  the  quarter  of  a horse 
from  the  ground  can  move  the  parts  of  w'hich  it  is  constructed  only 
with  great  velocity. 

If  you  load  a man  with  no  more  than  he  can  stand  under  upon 
one  foot,  he  can  walk  with  the  load.  A man  can  raise  his  whole 
body  upon  his  hands,  and  therefore  can  move  his  hands  with  great 
velocity  when  they  are  put  into  motion  without  the  body. 

The  Effects  arising  from  the  different  Constructions  of  Muscles. 

The  straight  narrow  muscle,  whose  fibres  run  parallel,  generally 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


253 


employs  all  its  fibres,  so  that  when  it  acts,  the  whole  muscle  is  in 
action  at  the  same  time. 

The  broad  and  radiated  muscles  do  not  always  employ  the  whole 
of  their  fibres  at  the  same  time,  each  part  often  acting  separately, 
like  separate  muscles  ; they  are  capable  of  taking  on  an  action  at 
any  one  part,  and  of  continuing  from  that  part  a succession  of 
actions  to  any  other  part,  or  through  the  whole  muscle;  and  they 
are  capable,  by  an  action  of  the  whole  muscle,  of  producing  one 
general  effect.  The  action  of  the  lateral  portions  of  such  muscles 
affects  the  tendon  somewhat  similar  to  the  complete-penniform ; 
therefore  the  middle  fibres  must  either  be  longer  than  the  lateral, 
or  have  a great  power  of  contraction,  which  will  be  better  un- 
derstoood  after  the  explanation  of  the  action  of  the  complete-penni- 
form. 

The  temporal  muscle  is  an  exception  to  the  ru-le  of  muscles  being 
made  radiated  to  produce  a succession  of  actions;  for  whatever 
part  of  this  muscle  acts,  nearly  the  same  effect  is  produced  ; such 
muscles,  cateris  paribus,  produce  effects  proportioned  to  their  length 
of  fibres. 

These  muscles  have  one  advantage,  which  is,  that  their  fibres 
are  much  longer  than  those  of  any  other  muscle  whose  body  is  of 
an  equal  length;  they  can  therefore  contract  much  more,  and  are 
always  used  in  the  more  extensive  motions. 

The  half-penniform  muscle  is,  I believe,  similar  in  its  action  to  the 
foregoing ; for  although  the  fibres  are  more  oblique,  the  tendon  is 
moveable  laterally,  so  as  to  move  nearly  in  the  same  line  with  the 
fibres.  This  kind  of  muscle  is  never  used  in  extensive  motions, 
except  where  there  is  considerable  distance  between  the  origin  and 
insertion,  to  admit  of  sufficient  length  of  fibres. 

Although  there  is  hardly  an  instance  of 
a complete-penniform  muscle  in  the  body,  a 
yet  as  all  the  complex  penniform  act  upon 
the  same  principle,  I shall  explain  the  ef- 
fects in  a supposed  complete-penniform, 
and  show  that  this  disposition  of  fibres 
produces  a greater  effect  than  any  of  the 
foregoing. 

In  the  action  of  these  muscles  we  sup- 
pose that  the  inserted  tendon  is  always 
moved  in  the  middle  line,  between  the  two 
origins  of  the  muscle,  and  therefore  the 
muscular  fibres  in  this  action  do  not  lose 
their  obliquity,  as  in  the  half-penniform, 
but  have  it  increased,  which  produces  a 
greater  effect. 

Let  A C and  B C represent  two  fibres 
of  a penniform  muscle  in  their  extended 
state,  A and  B being  their  origin,  and  C 
the  point  of  insertion  into  the  tendon  C D. 

23 


D 


254 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Suppose  these  fibres  contracted  to  the  points  E and  F,  it  is  evident 
that  such  contraction  will  bring  the  point  of  insertion  from  C to  G, 
and  that  the  motion  of  the  tendon  will  be  to  the  contraction  of  the 
muscle  as  C G is  to  C F or  C E ; for  A G is  equal  to  A E,  and  B 
G equal  to  B F,  or  A and  B are  the  centres  of  the  circles  AGE 
and  B G F. 

The  advantage  arising  form  this  construction  of  muscle  is  great, 
as  it  allows  of  a great  number  of  fibres  in  small  bulk,  and  is  there- 
lore  used  where  strength  is  required.  It  is  also  used  where  the 
quantity  of  motion  required  is  greater  than  the  distance  between 
the  origin  and  insertion  would  admit  of  in  any  other  construction, 
of  muscle. 


22.  CROONIAN  LECTURE  ON  MUSCULAR  MOTION,  No.  III. 

[Read  before  the  Royal  Society  in  the  year  1779,  by  John  Hunter,  F.R.S.] 

Of  the  Effects  of  Muscles. 

In  the  spring  of  1776  I had  the  honour  of  delivering  to  this  Society 
the  Croonian  Lecture  upon  the  self-moving  power  in  animals  seated 
in  the  muscles,  in  which  I also  made  some  observations  on  the 
analogy  between  this  power  in  animals  and  a similar  power  in 
vegetables. 

I was  then  desired  to  prosecute  this  subject,  and  accordingly,  in 
the  winter  following,  I presented  a paper,  in  which  I considered  the 
most  remarkable  circumstances  relative  to  this  power  in  animals, 
through  which  they  are  enabled  to  perform  all  their  various  mo- 
tions,— such  as  the  arrangement  of  the  fibres  in  the  construction  of 
all  the  muscles  ; the  distinct  muscles,  their  figure,  kinds,  and  situation  ; 
the  tendons,  and  fasciae,  with  their  uses ; the  applications  of  muscles 
to  tendons,  their  origin  and  insertion,  and  the  fitness  of  them  to  the 
joints.  It  was  here  noticed  that  their  effect  in  some  cases  is  equal 
to  their  quantity  of  contraction  ; in  others  not.  The  different  quan- 
tity of  contraction  in  the  same  length  of  fibres  in  different  muscles 
was  observed,  and  the  effect  arising  from  the  different  construction 
of  muscles. 

As  the  muscles  are,  by  their  contraction,  the  cause,  either  im- 
mediate or  remote,  of  every  action  in  the  animal,  and  as  animals 
are  so  constructed  as  to  produce  evident  mechanical  effects,  arising 
from  an  application  or  combination  of  the  mechanical  powers  (the 
contraction  of  the  muscles  being  the  power  or  original  cause),  I 
shall  now  consider  this  mechanical  application  and  its  effects,  with 
which  I shall  slightly  compare  the  applications  and  effects  of 
the  mechanical  powers  as  applied  in  machines  which  are  the  pro- 
ductions of  art. 

Muscles  are  the  first  simple  powers  in  an  animal,  by  which  all 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


255 


the  mechanical  effects  are  ultimately  produced  ; but  an  animal  body 
is  very  differently  constructed  from  that  of  a machine. 

A machine  is  composed  of  a series  of  parts,  having  a regular  de- 
pendence on  each  other ; and  the  power  which  produces  motion  is 
applied  only  at  one  end  of  these  parts,  although  two,  three,  or 
more  effects  may  ultimately  be  produced,  which  effects,  notwith- 
standing, must  therefore  arise  from  the  multiplication  of  the  parts 
of  the  machine,  and  not  from  the  increased  number  of  powers. 

But  an  animal  is  composed  of  parts,  each  part,  and  each  motion 
of  each  part,  having  its  own  moving  power,  capable  of  producing 
its  immediate  and  remote  effects  independent  of  each  other;  so 
that  in  animals  many  effects  may  be  going  on  at  one  and  the  same 
time,  and  each  actuated  by  its  own  peculiar  power,  by  which 
means  an  innumerable  variety  of  effects  arc  carried  on  at  the  same 
time,  and  without  the  least  confusion  or  interference  with  each 
other. 

A muscle,  as  to  itself,  may  be  considered  in  two  lights,  one  re- 
specting its  quantity  of  contraction,  and  the  other  its  power,  both 
of  which  produce  considerable  effects  in  the  body,  and  each  is 
employed  according  to  circumstances. 

Every  muscle  in  an  animal  body  may  be  considered  as  a simple 
independent  power;  and  if  we  attend  to  the  effects  that  many 
animals  are  capable  of  producing,  particularly  the  motion  of 
fishes  and  the  flight  of  birds,  we  shall  see  great  reason  to  admire 
the  immense  velocity  and  great  force  with  which  their  muscles 
are  contracted  ; and  if  we  compare  the  effects  produced  by  the 
contraction  of  their  muscles  with  the  weight  of  each  muscle 
and  the  part  which  is  to  move,  it  may  lead  us  to  conclude  that 
there  probably  is  not  in  nature  a more  active  simple  power 
than  the  contraction  of  the  animal  muscles.  An  animal  is  per- 
haps the  only  machine  that  has  the  power  of  overcoming  its 
own  gravity. 

In  considering  animal  bodies  in  general  in  a mechanical  light, 
we  should  first  attend  to  the  most  simple  mode  of  action  in  the 
animal,  or  the  mode  of  action  of  the  muscles  in  the  most  simple 
animal,  and  proceed  from  the  most  simple  to  the  most  compound 
or  complicated,  in  which  latter  may  be  discovered  applications  and 
combinations  of  the  several  mechanical  powers  (which  for  beauty, 
simplicity,  regularity,  and  aptness  far  excel  all  human  applications), 
in  order  to  produce  the  manifold  effects  of  animal  motion,  and  to 
accommodate  the  ultimate  velocity  or  force  at  the  same  time  to  the 
particular  effects  to  be  produced,  as  well  as  to  the  simple  power  of 
contraction  in  the  several  muscles  which  act  as  first  movers  in 
producing  that  effect. 

In  many  animals  the  parts  endowed  with  the  first  principles  of 
motion,  viz.,  the  muscular  fibres,  are  themselves  formed  in  various 
shapes,  so  as  to  constitute  complete  animals  of  the  most  simple 
fibres;  and  even  in  the  most  complicated  animal  many  distinct 
parts  are  composed  of  those  moving  powers,  forming  regular 


256 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


bodies,  called  organs,  comnaonly  producing  of  themselves  a vast 
variety  of  effects,  by  which  means  many  of  the  numberless  internal 
actions  respecting  the  animal  ceconomy  are  carried  on;  so  that 
even  in  those  more  complicated  animals  we  have  the  first  organiza- 
tion formed  of  muscular  fibres  alone,  in  the  same  manner  as  in  the 
more  simple  animals.* 

This  would  lead  us  to  consider  the  effects  of  muscular  contraction 
in  very  different  views,  viz.,  according  to  the  various  effects  they 
are  capable  of  producing  in  animals  of  all  the  various  constructions 
and  complications. 

In  many  of  the  moi’e  simple  animals  there  is  little  else  besides 
those  formations  or  organizations  composed  of  muscles.  A polypus 
is  little  more  than  a muscular  bag,  and  by  the  contraction  of  its 
fibres  in  different  parts,  and  in  different  directions  at  different  times, 
the  bag  is  changed  into  various  forms  and  sizes. 

A worm  seems  a little  more  complicated  : however  it  is  in  reality 
little  more  than  a body  formed  of  different  parts,  each  of  which  is 
composed  of  muscle.  A slug,  a maggot,  as  also  numberless  tribes 
of  sea-animals,  come  under  the  same  description. 

But  as  animals  emerge  from  this  simplicity  of  construction,  be- 
coming more  and  more  complicated,  having  particular  parts 
added,  and  those  parts  being  composed  of  something  besides  mus- 
cle, and  it  also  being  necessary  that  these  should  move,  and  be  so 
constructed  as  to  direct,  circumscribe,  increase,  or  limit  the  motion, 
we  find  the  muscular  fibres  of  such  animals  collected  into  various 
portions  and  forms,  in  order  to  give  all  the  different  motions  to  these 
superadded  parts  which  were  taken  notice  of  in  the  former  lecture. 
Those  additional  parts  are  composed  of  more  rigid  matter  than 
muscle,  viz.,  bones,  cartilages,  &c.,  on  which  the  muscles  can  have 
no  other  influence  than  by  giving  them  motion.  There  are  a 
number  of  those  bones,  cartilages,  &c.,  in  many  animals,  some 
having  moi’e,  some  fewer;  and  they  are  connected  in  such  a 
way  as  to  form  between  them  intervals  fit  for  motion,  called  joints: 
in  most  parts  of  the  body  there  is  a series  of  those  bones  and  joints, 
as  the  spine,  the  extremities,  &c. 

Many  of  these  bones  are  so  formed,  and  so  placed  and  connected 
with  one  another,  as  to  form  levers  (and  those  of  all  the  various 
kinds),  which  direct  and  limit  the  motions,  so  as  to  produce  a regu- 
larity in  the  whole. 

As  the  relative  inclinations  and  positions  of  those  several  bones 
which  are  immediately  connected  and  joined  together  are  very 
various,  it  follows  that  there  must  be  a variety  in  the  angle  of  in- 

* [Hunter  here  compares  the  first-formed  parts  of  the  vertebrate  embryo, 
derived  from  the  mutually  receding  layers  of  the  germinal  membrane  and  the 
folding  of  those  layers,  with  the  simple  homogeneous  tissue  of  the  hydra  or  other 
acrite  animal.  And,  as  he  applies  the  term  muscular  to  the  contractile  tissue  of 
these  animals,  so  he  would  also  regard  the  homogeneous  gelatinous  parietes  of 
the  newly  formed  digestive  sac  of  the  embryo  of  the  higher  organized  species  as 
being  in  like  manner  endowed  with  contractility,  and  therefore  ‘ formed  of  mus- 
cular fibres,’  or  contractile  substance  ‘aloile.’ 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


257 


sertion  of  the  several  muscles,  to  accommodate  them  to  the  particular 
circumstance  of  each  joint.  And  as  those  inclinations  vary  in  the 
motions  of  the  joint,  so  must  the  angle  of  insertion  of  the  muscles 
which  will  produce  a difference  in  the  effects,  both  in  the  power 
and  quantity  of  contraction. 

To  this  great  variety  of  these  levers  and  joints  we  have  the  mus- 
cles adapted. 

We  may  observe,  that  the  more  perfect  the  animal  is,  the  more 
curiously  these  levers  and  joints  are  formed,  the  joints  commonly 
consisting  of  compound  curves  (which  is  the  most  remarkable  in 
the  more  perfect  animals),  by  which  means  their  own  motions 
admit  of  greater  variety. 

The  human  subject  is  a striking  instance  of  this,  having  the.joints 
more  compounded,  and  the  motions  less  limited,  than  in  any  other 
animal  that  I know,  which  circumstances  require  a greater  variety 
of  muscle,  and  the  greater  nicety  in  the  adapting  of  each  muscle 
to  produce  its  peculiar  motion. 

In  the  most  perfect  animals  there  are  very  few  joints  whose  mo- 
tion is  simple,  or  which  are  confined  on  all  occasions  to  move  in 
one  direction  ; for  whatever  may  be  their  cliief  or  ordinary  motion, 
in  many  there  is  some  other  motion  compounded  with  it;  nor  are 
there  many  joints  which  move  upon  one  centre  in  all  their  motions, 
but  they  shift  their  centre  as  the  curve  varies.* 

These  firm  inflexible  substances  are  kept  together  by  soft,  yield- 
ing yet  sufficiently  strong  parts,  called  ligaments,  which  are  neces- 
sarily so  constructed  and  placed,  with  respect  to  the  motion  of  the 
joint,  as  to  produce  an  effect  analogous  to  that  of  a centre  pin  in 
a plain  circular  joint,  and  in  all  the  vai'ious  situations  of  the  centres 
of  motion. 

I may  be  allowed  to  observe,  previous  to  entering  upon  the 
mechanical  motions  produced  by  the  muscles  in  an  animal  body, 
that,  without  external  resistance,  there  would  be  no  such  thing  as 
progressive  motion  in  an  animal ; for  although  a muscle  has  the 
power  of  contraction  in  itself,  and  is  capable  of  moving  all  its  differ- 
ent parts  upon  itself,  yet  it  cannot  move  any  other  part  without 
having  some  fixed  point  to  act  from,  which  is  the  greatest  point  of 
resistance.  There  is  in  every  animal,  therefore,  a fixed  point  from 
which  the  parts  of  the  body  take  their  principal  motions.  In  the 
human  body  this  fixed  point  seems  to  be  in  the  joints  of  the  thigh- 
bones ; which  point,  being  in  the  middle  of  the  body,  must  be  com- 
mon to  the  extremities.  We  see,  therefore,  that  the  body  either 
moves  on  the  legs,  or  that  the  legs  move  on  the  body  or  trunk. 
Besides  this,  there  are  many  fixed  points,  so  that  the  body  is  to  be 
looked  upon  as  a chain  of  joints  whose  general  centre  of  motion  is 
in  the  joints  of  the  thighs ; but  each  has  its  fulcrum,  or  centre  of 
motion,  which  is  always  on  that  side  next  to  the  first,  or  the  general 


* A remarkable  instance  of  this  we  have  in  the  joint  of  the  lovper  jaw  in  grami- 
nivorous animals. 

23* 


258 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


centre  of  motion  of  the  whole,  by  which  means  the  smaller  moves 
upon  the  greater,  the  toe  upon  the  foot,  the  foot  upon  the  leg,  the 
leg  upon  the  thigh,  and  the  thigh  upon  the  body.  The  same  in  the 
arms,  the  wings  of  birds,  the  tails  of  fishes,  the  oars  of  a boat,  &c. 
But  those  motions  can  be,  and  often  are,  inverted,  so  that  the 
greater  can  be  made  to  move  upon  the  smaller ; as,  for  instance, 
the  body  upon  the  thigh,  the  thigh  upon  the  leg;  or,  in  birds,  the 
body  upon  the  wing,  &c. ; but  then  the  smaller  must  be  so  circum- 
stanced as  to  be  the  fixed  point,  which  cannot  be  without  external 
resistance.  It  is  the  inverted  motions,  then,  which  produce  the 
progressive;  but  it  is  necessary,  for  the  production  of  a succession 
of  them,  to  bring  in  also  the  motion  of  smaller  parts  upon  greater; 
the  two  kinds  of  motion  are,  therefore,  acting  alternately  whenever 
the  progressive  motion  is  continued  beyond  the  first  action. 

The  animals  which  move  upon  the  earth  have  it  for  their  point 
of  resistance.  Birds  are  supported  and  propelled  in  their  flight  by 
the  resistance  of  the  air  ; and  fishes,  like  boats,  by  the  resistance  of 
the  water. 

The  eflects  of  muscular  contraction  may  be  divided  into  three 
kinds. 

The  first  is,  where  the  eflects  are  in  those  parts  of  the  body  which 
are  principally  composed  of  muscle  : these  simply  vary  their  con- 
figuration without  extending  their  power  beyond  themselves,  as  in 
the  actions  of  many  of  the  more  imperfect  tribes  of  animals,  as  the 
leech,  polypus,  &c.,  and  in  many  parts  of  the  more  perfect  animals, 
as  the  heart,  stomach,  intestines,  bladder,  and  all  the  vascular 
system.* 

The  second  is  where  the  effect  is  more  extended  and  reaches 
beyond  the  muscles  themselves  to  such  adjoining  parts  as  are  either 
formed  simply  for  motion,  as  bones,  cartilages,  &c.,  or  whole  parts 
of,  the  body,  such  as  an  eye,  a lip,  the  skin,  &c. 

The  third  is  where  the  eflects  are  mixed,  viz.,  partake  of  both  the 
preceding,  as  in  those  produced  by  the  muscles  of  the  tongue,  of 
respiration,  of  the  abdomen,  &c.,  where  they  both  move  parts  and 
alter  their  configuration. 

The  first  and  third  kind  of  eflects  of  muscles,  when  considered 
in  the  more  perfect  animals,  are  more  connected  with  the  internal 
ceconomy  of  the  animal  than  with  the  mechanical  application  of 
the  power  of  muscular  contraction  ; therefore  in  them  it  is  the 
second  whicli  comes  properly  under  consideration,  as  mechanical, 
since  it  produces  visible  mechanical  eflects  upon  parts  formed  for 
motion,  and  evidently  calculated  to  vary  the  velocity  from  that  of 
the  first. 

The  application  of  muscles  in  an  animal  body  is  either  to  pro- 
duce a quantity  of  motion  equal  to  the  quantity  of  contraction  of 
the  muscle ; or,  by  the  application  of  levers,  to  give  a greater 

* [This  is  not  exactly  true  of  these  viscera,  for  their  contents  ejected  by  the 
contraction  of  the  surrounding  fibres  act  upon  the  parts  into  which  they  are  pro- 
pelled, as  the  bone  moved  by  the  muscle  inserted  into  it  also  carries  the  part 
connected  with  it  along  with  it  in  its  motions.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


259 


motion  than  could  be  produced  by  the  simple  contraction  of  the 
muscle.  This  in  general  is  not  the  case  in  machines  composed  by 
art;  for  in  art  the  principal  reason  for  the  introduction  of  me- 
chanics is  to  acquire  power  in  the  effect,  which  obliges  us  to 
increase  the  velocity  in  the  moving  cause,  as  in  levers  and  pulleys. 
However,  this  is  not  universal  in  machines  ; for  some  have  it 
reversed,  as  the  catapulta,  the  lock  of  a gun,  and  also  in  many 
machines  where  strength  is  not  the  object,  but  velocity  in  some  par- 
ticular movements,  as  in  watches,  jacks,  &c. 

Whether  the  effect  of  a given  quantity  of  contraction  in  a muscle 
be  or  be  not  equal  to  that  quantity  depends  upon  the  construction 
and  disposition  of  the  parts  to  be  moved,  or  the  form  which  the 
whole  muscle  is  thrown  into.  Thus  the  effects  of  some  muscles 
upon  the  parts  are  just  equal  to  the  contraction  of  the  muscular 
fibres ; such  are  those  which  simply  draw  parts  to  them,  not  vary- 
ing the  position  of  the  part  moved  from  the  right  line,  as  many  of 
the  muscles  of  the  larynx,  the  trapezius,  rhomboideus,  and  all  of 
the  panniculus  carnosus  kind,  as  the  muscles  of  the  face,  platysma 
myoides,  and  the  muscles  of  the  skin  of  animals. 

Another  class,  whose  effects  are  always  known,  or  are  the  same 
in  all  cases,  are  those  muscles  which  produce  their  effects  from  the 
shape  which  the  muscle  is  thrown  into,  for  instance,  a curve. 
Curved  muscles  are  of  two  kinds,  viz.,  those  which  are  fixed  at 
their  ends,  as  the  abdominal  muscles,  pharynx,  &c.,  and  those 
which  are  circular,  as  the  sphincters,  heart,  and  the  whole  vascular 
system.  These  muscles  always  reduce  the  circumference  and,  of 
course,  the  diameter  of  the  circle,  which  they  themselves  compose, 
in  proportion  to  their  quantity  of  contraction ; but  the  ultimate 
effect  here  is  not  in  proportion  to  the  quantity  of  contraction,  but 
decreases  as  the  squares  of  the  diameters  of  such  vessels.  But 
most  parts  of  the  body  are  so  mechanically  formed,  acting  as  levers, 
and  the  muscles  so  advantageously  inserted,  as  to  produce  a much 
greater  degree  of  velocity  in  the  motion  of  the  part  than  is  equal 
to  the  contraction  of  the  muscle.  But  those  mechanical  applica- 
tions are  so  various  that  there  are  no  two  muscles  wdiich  act  with 
the  same  advantages,  excepting  those  that  are  in  pairs.  On  this 
application  of  muscles  to  levers  depends  the  distinction  between 
the  absolute  and  apparent  force  of  muscles,  neither  of  which  can 
possibly  be  ascertained  with  any  degree  of  certainty. 

Every  muscular  fibre  is  capable  of  contracting  with  a given 
pow’er,  which  power  simply  must  be  always  its  absolute  force ; 
but  from  the  construction  of  parts  to  be  moved,  and  the  applica- 
tion of  muscles  to  those  parts,  either  an  increased  or  decreased 
effect  is  produced. 

It  is  impossible  to  ascertain  the  absolute  force  of  a muscle 
because  there  is  no  one  known  muscle  in  the  body  that  we  can 
throw  into  action  separately,  and  independently  of  the  collateral 
effects  ot  others.  And,  if  we  could,  there  are  many  whose  power 
could  not  be  measured  by  any  given  quantity  of  resistance  to  be 


260 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


overcome,  so  as  to  ascertain  the  power  of  contraction  of  that 
muscle,  as,  e.  g.,  all  those  which  simply  pull  bodies  in  a straight 
line  : but,  in  those  muscles  which  act  upon  the  bones  in  the  form  of 
levers,  if  any  could  be  made  to  act  singly  its  power  could  easily 
be  known.  But  whatever  this  power  is  it  must  be  always  the 
same ; nothing  can  alter  it  excepting  real  weakness  in  the  muscular 
fibres  themselves. 

As  we  cannot  separate  and  ascertain  the  absolute  force  of  a 
single  muscle,  so  it  is  impossible  to  find  out  the  apparent  force  ; 
and  exactly  for  the  same  reasons  that  we  cannot  find  out  the  abso- 
lute. The  apparent  force  of  circular  muscles  will  be  in  a ratio 
proportionably  to  their  diameters,  and  in  those  which  are  inserted 
into  levers  it  will  always  be  as  the  distance  of  the  insertion  of  the 
muscle  from  the  centre  of  motion,  the  angle  of  insertion,  &c.  But 
the  relative  force  is  not  always  the  same,  or  it  does  not  always  act 
alone  in  the  motion  of  the  parts,  for  it  is  often  joined  with  velocity, 
and  then  it  may  become  vastly  greater.  But  if  not  joined  with 
velocity  it  will  always  be  less  than  the  absolute,  as  the  length  of 
lever  in  the  resisting  power  is  longer  than  in  the  acting  one. 

The  absolute  force  of  a muscle  will  always  be  employed  in  the 
most  simple  action  of  the  parts.  The  most  simple  action  will  be 
where  a muscle  passes  in  a straight  line  from  some  fixed  point  to 
a moveable  one,  and  by  its  contraction  simply  pulls  the  moveable 
one  towards  the  immoveable  one,  such  as  many  of  the  muscles  of 
the  os  hyoides,  and  in  many  other  parts  of  the  body. 

As  the  circular  muscles  are  commonly  employed  in  propelling 
bodies,  and  principally  fluids,  they  will  keep  up  an  equal  power 
upon  the  body  to  be  expelled ; for,  the  power  increasing  as  the 
fluid  decreases,  it  is  capable  of  throwing  out  the  same  quantity  in 
the  same  time.* 


I observed  that  the  muscles,  as  moving  powers  in  an  animal, 
differ  from  the  moving  powers  in  a machine,  the  production  of  art, 
inasmuch  as  every  part  had  its  power  adapted  to  the  motion  it  is 
capable  of,  and  therefore  the  motion  of  any  one  part  did  not  depend 
entirely  upon  its  own  configuration  and  connexion  with  some  other. 
Although  this  is  in  a srreat  measure  the  truth,  yet  the  motion  in 
most  parts  is  assisted  by  actions  or  the  contrary  in  other  parts,  so 
that  there  is  a kind  of  dependence  and  mutual  assistance  through 
the  whole.  This  does  not,  however,  arise  from  any  mechanical 
construction,  but  from  a connexion  of  the  living  principle  in  the 
pow'ers  of  one  part  with  those  of  another,  which  may  be  termed  a 
species  of  intelligence. 

The  motion  of  parts  generally  is  the  motion  of  a smaller  upon  a 
greater,  and  the  greater  becomes  the  fixed  point  upon  which  the 

* It  may  be  asked,  at  what  point  of  the  contraction  of  a muscle  has  it  the 
greatest  power  ? Or,  does  it  contract  with  the  same  force  through  the  whole 
contraction  ? 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


261 


smaller  may  be  said  to  move;  but  we  find  that  there  are  few  mo- 
tions, however  trifling,  but  what  affect  the  greater  part;  therefore 
that  this  motion  in  the  smaller  part  may  be  more  effectual  and  an- 
swer the  intended  purpose,  the  greater  part  is  either  thrown  into  a 
counter-motion  by  its  own  muscles,  or  it  is  supported  in  its  place 
by  them,  or  it  is  thrown  into  the  same  action  with  the  small  part, 
so  as  to  increase  it.  Hence  the  actions  of  these  powers  may  be 
said  to  be  of  two  kinds,  immediate  and  secondary. 

The  first  is  that  which  produces  the  immediate  action  of  the 
part;  the  second  produces  the  assistant,  supporting,  regulating 
actions,  &c.  For  instance,  when  a man  walks,  it  at  first  might 
appear  that  the  only  thing  necessary  to  produce  the  ultimate  effect 
was  the  motipn  of  the  two  legs,  the  body  being  first  thrown  suffi- 
ciently forwards,  so  as  always  to  require  that  motion  of  the  legs  to 
support  the  centre  of  gravit}u  But  this  is  not  sufficient ; it  is  ne- 
cessary that  the  muscles  of  the  trunk  should  act,  and  regulate  the 
body  so  as  to  support  the  centre  of  gravity  on  all  sides.  If  the 
right  leg  moves,  the  muscles  of  the  left  side  of  the  trunk  act  to  sup- 
port the  whole  on  the  left  leg,  and  vice  versa;  so  that  the  body 
plays  upon  the  motion  of  the  legs,  by  which  means  the  legs  have 
much  less  to  do,  and  therefore  can  support  it  longer. 

In  many  of  the  actions  of  parts  of  the  body  other  parts  are  kept 
immoveable,  although  they  would  appear  to  have  nothing  to  do 
with  any  such  actions.  A man  never  performs  any  considerable 
action,  even  with  any  of  the  extremities,  without  the  trunk  being 
more  or  less  affected,  so  as  to  favour  the  motion  of  the  extremity. 
We  find  that  we  first  make  a full  inspiration  and  that  all  the  muscles 
of  respiration  act,  also  the  muscles  of  the  glottis,  and  of  the  soft 
palate,  so  as  to  confine  the  air  which  makes  the  trunk  as  rigid  and 
firm  as  possible  to  support  or  sustain  the  actions  and  motion  of  the 
extremity. 

If  an  action  takes  place  in  an  extremity,  where  a considerable 
effect  is  to  be  produced,  which  can  only  be  produced  by  a consi- 
derable velocity,  then  the  whole  body  gives  it  assistance  so  far  as 
it  is  possible  for  it  to  do. 

If  a man  throws  a stone,  or  a blacksmith  swings  his  sledge- 
hammer, the  whole  body  humours  the  action,  and  the  fixed  point 
is  thrown  to  a greater  distance  than  the  setting-on  of  the  arm:  the 
whole  moves  from  the  loins,  or  perhaps  lower. 

Those  secondary  actions  are  brought  in  as  auxiliaries,  and  an- 
swer two  very  important  purposes : they  increase  the  quantity  of 
action  when  necessary,  and  they  assist  in  easing  the  immediate 
action,  so  as  to  allow  of  a continuance  of  it,  by  which  means  ani- 
mals are  capable  of  performing  greater  actions,  with  more  ease, 
and  a longer  continuance. 

Muscles  regulate  the  actions  of  others  not  only  by  their  contrac- 
tion but  by  their  relaxation,  which  last  is  a kind  of  negative  action. 
When  a man  walks  I have  already  observed  that  there  are  many 
muscles  acting  as  secondary  agents  in  the  body,  so  as  to  assist  the 


262 


HUNTER  ON  THE  ANIMAL  CEUONOMY. 


immediate  motions  of  the  part  to  be  moved;  but,  besides  this,  there 
are  many  of  the  same  muscles  that  are  gradually  relaxing,  so  as  to 
allow  the  alternate  motions  by  imperceptible  degrees  to  creep  regu- 
larly into  one  another. 

Perhaps  I cannot  give  a more  striking  idea  of  those  primary  and 
secondary  actions,  with  the  relaxations,  which  I have  called  nega- 
tive actions,  than  to  present  to  the  minds  of  those  who  have  some 
knowledge  of  the  subject  what  must  be  going  on  with  the  muscles 
of  a man  balancing  himself  on  a slack  or  tight  rope,  when  the  first 
or  immediate  order  of  muscles  are  acting  with  their  utmost  force; 
where  the  secondary  are  assisting  in  the  secondary  actions  of  the 
body,  and  as  it  were  playing  into  the  hands  of  the  first;  where 
others  again  are  relaxing  in  proportion  as  the  first  and  second  are 
acting  ; and  where  the  entirely  relaxed  are  waiting  the  opportunity 
to  act,  when  called  upon  by  any  change  that  shall  take  place  in  the 
position  of  the  body,  which  in  such  circumstances  is  in  acontinued 
agitation. 


23.  CROONIAN  LECTURE  ON  MUSCULAR  MOTION,  No.  IV. 

[The  manuscript  of  this  Lecture  appears  not  to  have  been  among 
those  which  were  accessible  to  Mr.  Clift,  and  from  his  copies  of 
which  the  Lectures  in  the  present  volume  have,  with  his  permission, 
been  printed.  Its  absence  may,  however,  be  accounted  for,  from 
the  fact  that  the  substance  of  the  Fourth  Croonian  Lecture  was  in- 
corporated by  Hunter  in  his  work  ‘On  the  Blood,’  (see  the  Chapter 
on  the  Vascular  System,)  as  is  evident  from  the  Abstract  of  the 
Lecture  in  the  Archives  of  the  Royal  Society,  the  subjoined  copy  of 
which  Abstract  Mr.  Palmer,  with  the  permission  of  the  President 
and  Council,  has  obtained  for  the  use  of  the  present  edition  of 
Hunter’s  Works.] 

[The  Croonian  Lecture  on  Muscular  Motion,  by  Mr.  John  Hunter,  was  read  on  the 
25th  of  May  and  1st  of  June,  1780.] 

“The  construction  and  general  application  of  muscles  in  the 
animal  body  having  been  discussed  by  our  author  in  three  former 
lectures,  he  now  proceeds  to  treat  of  the  action  of  muscles  on  the 
blood-vessels,  an  inquiry  which,  however  essentially  it  may  contri- 
bute to  our  better  acquaintance  with  the  animal  oeconomy,  has  yet, 
it  seems,  till  now  been  but  little  attended  to,  the  existence  of  mus- 
cular fibres  in  the  system  of  blood-vessels  being  by  no  means 
obvious. 

“ Mr.  H.  finds  it  necessary  previously  to  lay  down  some  general 
principles  concerning  muscles,  which  he  derives  from  their  opera- 
tions in  those  parts  of  the  animal  where  their  uses  are  well  un- 
derstood. 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


263 


“ A muscle  he  defines  such  an  arrangement  of  animal  matter  as, 
whilst  it  is  endowed  with  life,  is  fitted  for  self-motion.  This  motion, 
he  says,  consists  in  the  contraction  of  the  muscular  fibres,  in  which 
light  he  considers  it  as  totally  distinct  from  elasticity.  And  he 
ventures  to  assert  that  no  part  of  an  animal  except  the  muscles  is 
endowed  with  this  power  of  self-motion.  He  acknowledges  soon 
after  that  this  power  cannot  be  the  sole  effect  of  contraction,  but 
that  there  must  also  be  a power  of  relaxation,  acting  alternately, 
without  which  no  effect  could  be  produced.  But  even  this  relaxa- 
tion, he  says,  is  not  sufficient  to  produce  any  effect  without  a pre- 
vious elongation ; and  as  no  muscle  is,  as  such,  possessed  of  this 
power  of  elongation,  he  considers  it  as  the  effect  of  antagonists  of 
some  kind  or  other,  or  of  what  may  be  called  the  elongators  of  the 
muscles,  and  says,  that  it  is  not  in  all  cases  muscular,  but  some- 
times the  effect  of  elasticity,  and  sometimes  even  of  matter  foreign 
to  the  body.  This  leads  him  to  distinguish  it  into  three  kinds;  the 
first,  where  it  is  immediately  muscular,  or  when  antagonist  mus- 
cles act  immediately  upon  each  other;  the  second,  when  a muscle 
acts  upon  some  other  matter,  and  gives  it  the  power  of  an  antago- 
nist, as  is  the  case  in  all  those  muscles  that  enter  into  the  formation 
of  canals  or  cavities,  whose  elongation  is  produced  by  other  mus- 
cles, which  have  no  immediate  connexion  with  them,  but  which 
force  them  to  an  extension  by  propelling  the  contents  of  the  canal, 
instances  of  which  we  find  in  the  oesophagus,  the  intestines,  and  the 
bladder ; and  thirdly,  when  the  elongation  is  owing  to  elastic  sub- 
stances, which  sometimes  cooperate  with,  and  sometimes  resist  the 
action  of  muscles ; and  of  other  powers,  such  as  gravitation, 
velocity,  &c. 

“ The  second  section  treats  of  the  application  of  the  muscular 
and  elastic  powers,  where  both  indisputa bl\"  act.  The  joint  applica- 
tion of  these  two  powers  vre  are  told  is  very  common,  though 
hitherto  it  has  been  but  little  noticed.  Elasticity  operates  where 
constant  or  stationary  action  is  wanted.  Muscles  are  applied  where 
occasional  action  is  required;  and  where  both  effects  are  wanted 
both  powers  cooperate.  This  is  illustrated  by  various  examples, 
among  the  rest  that  of  a bivalve,  which  has  a muscle  between  the 
two  shells,  for  the  purpose  of  closing  them,  and  an  elastic  ligament 
in  the  joint,  which  constantly  tends  to  diverge  them. 

“Another  instance,  much  more  to  the  present  purpose,  is  that  of 
the  elastic  cartilages  and  membranes  of  the  trachea,  and  its  branches, 
which  maintain  an  equilibrium  by  counteracting  the  tendency  the 
muscles  of  respiration  have  to  contract  that  channel. 

“ In  most  parts  of  the  body  the  muscles  are  so  well  defined  that 
their  existence  is  evinced  by  merely  viewing  their  structure  and 
colour.  But  this  is  not  always  the  case,  and  we  especially  find  that 
in  the  blood-vessels  no  traces  of  muscles  are  distinguishable  by  mere 
inspection. 

“ Here  then  other  modes  of  information  are  requisite,  and  our 
author  proposes  two.  The  one  is  their  effect  when  we  see  actions 


2G4 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


that  are  in  every  respect  muscular,  although  no  muscle  be  distin- 
guishable by  the  eye  ; and  the  other  the  change  that  takes  place  after 
death,  when,  as  Mr.  H.  has  observed,  in  many  cases  the  power  of 
contraction  preponderates  so  as  to  stilTen  all  the  muscular  parts  ; 
and  when,  if  the  muscles  thus  contracted  be  afterwards  stretched 
or  pul  into  what  in  the  living  body  may  be  called  its  relaxed  state, 
they  remain  thus  relaxed  without  showing  the  least  tendency  to  any 
further  contraction.  These  circumstances  mark  the  difference 
between  muscular  and  elastic  parts,  since  this  latter  power  continues 
to  act  after  death  much  in  the  same  manner  as  it  did  during  the  life 
of  an  animal. 

“ These  two  modes  of  information  are  next  applied  in  the  exami- 
nation of  blood-vessels,  which,  our  author  previously  observes, 
seldom  bear  any  visible  marks  of  muscular  construction,  and  scarce 
ever  admit  of  examining  from  their  effects  in  the  living  body,  on 
which  account  the  second  mode  of  information  must  be  adopted  as 
the  likeliest  to  furnish  some  lights  in  this  inquiiy.  He  made  a set 
of  experiments  on  the  blood-vessels  of  a dead  horse,  which  were 
taken  out  so  carefully  as  not  to  affect  in  the  least  either  their  texture 
or  degree  of  contraction.  They  were  examined  both  in  their  natural 
state  and  after  they  had  been  ojrened,  and  stretched  different  ways, 
by  which  means  the  different  actions  of  the  muscular  and  of  the 
elastic  powers  become  easily  discernible.  The  following  are  the 
principal  facts  that  resulted  from  this  examination; 

“Every  part  of  the  vascular  system  is  not  equally  endowed  with 
muscles ; the  larger  vessels,  especially  the  arteries,  being  chiefly 
composed  of  elastic  substances,  whilst  many  parts  of  the  smaller, 
or  what  are  called  the  capillary  vessels,  appear  to  be  almost  entirely 
muscular. 

“ In  the  middle-sized  arteries  two  substances  are  visible  to  the 
eye,  that  towards  the  inner  coat  being  evidently  darker  in  colour, 
and  of  a structure  somewhat  different  from  the  outward.  The 
relative  thickness  of  these  coats  differs  as  we  recede  from  the  heart, 
the  interior  becoming  considerably  thicker  in  proportion  to  the 
exterior;  whence  it  evidently  follows  that  the  external  diameter  of 
the  duct  is  not  to  be  inferred  from  its  external  thickness,  this 
being  always  proportionably  greater  as  the  vessel  diminishes  in  size. 
Both  these  coats  are  in  some  measure  elastic,  but  the  external  is 
more  so  than  the  internal;  whence  it  may  be  judged  that  it  is  the 
internal  tliat  is  endowed  with  muscular  properties.  This  indeed  is 
confirmed  by  a variety  of  experiments,  in  which  it  was  found  that 
the  inner  surface  after  death  was  considerably  more  contracted 
than  the  outward,  the  latter  being  thrown  into  longitudinal  corruga- 
tions, which  could  only  be  the  effect  of  the  greater  transverse  or 
circular  contraction  of  the  latter. 

“ It  has  further  been  observed  that  this  muscular  contraction  is 
chiefly  in  the  transverse  direction,  and  seldom  if  ever  longitudinal, 

“ The  physiological  application  of  these  facts,  especially  to  arte- 
ries, is  briefly  this.  The  muscular  contraction  being  chiefly  circu- 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


265 


lar,  and  tending  to  lessen  the  diameter  of  the  vessel,  the  animal 
(Economy  would  suffer  greatly  if  in  the  larger  arteries,  where  this 
contraction  is  greater  in  proportion  as  its  diameter  increases,  some 
power  did  not  counteract  this  tendency  so  as  to  maintain  a middle 
state  or  equilibrium.  Thus  also  when  muscular  parts  are  too  much 
distended,  which  in  large  arteries  will  often  happen  on  account  of 
their  vicinity  to  the  heart,  a similar  power  is  requisite  to  contract  it 
to  its  natural  size  or  tone.  In  both  cases  the  elastic  power  pro- 
duces the  necessary  effect,  and  it  seems  to  follow  hence  that  this 
power  must  always  be  proportionally  greater  in  the  larger  vessels 
than  in  the  smaller  ones. 

“ A Table,  exhibiting  at  one  view  the  results  of  the  above-men- 
tioned experiments  concludes  this  lecture.”* 


24.  CROONIAN  LECTURE  ON  MUSCULAR  MOTION, No.  V. 

FOR  THE  YEAR  1781. 

[Read  before  the  Royal  Society,  June  14,  by  Mr.  John  Hunter,  F.R.S.] 

Of  the  Contraction  and  Relaxation  of  Muscular  Fibres. 

Muscular  motion  differs  from  every  other  motion  in  matter;  it 
is  a motion  taking  place  in  the  component  parts  of  a muscle,  and 
not  a change  of  their  relative  situation.  It  is  an  uniform  approxi- 
mation, and  receding  in  all  the  parts ; the  size,  construction,  and 
connexion  of  these  are  as  yet  not  known  : it  is  similar,  as  far  as  we 
can  discover  by  our  senses,  to  elasticity;  in  both  cases  the  motion 
is  produced  in  the  component  parts,  which  we  are  as  yet  unac- 
quainted with,  and  only  see  the  ultimate  effect. 

For  the  better  investigating  this  motion  in  muscles,  we  may 
divide  the  general  motions  in  matter  into  four  kinds. 

* [The  irritability,  or  muscularity,  of  part  of  the  coats  of  the  artery  contended 
for  in  the  preceding  lecture  by  Hunter,  has  since  been  demonstrated  experi- 
mentally, first,  by  Dr.  John  Thompson  of  Edinburgh,  and  subsequently  by  many 
other  physiologists ; in  whose  experiments  distinctcontraction  of  the  small  arteries 
■was  produced,  not  only  by  mechanical  (Wilson  Philip,  Hastings,  Kaltenbrunner) 
but  by  galvanical  irritation.  (See  TViedemeyer,  Experimenta  circa  Statum  San- 
guinis et  Vasnrum  in  Injlammatione,  Monachii,  4to.,  1826,  and  the  Bibliography 
of  the  Vascular  System,  vol.  iii.,  p.  226.)  The  muscular  action  is  easily  seen 
by  dropping  water  colder  than  the  atmosphere  upon  the  capillaries  in  [the 
mesentery  of  a frog,  which  thereupon  contract  both  longitudinally  and  transverse- 
ly, and  after  a little  while  resume  their  ordinary  dimensions.  Nev^ertheless 
the  best  chemists  agree  in  classing  the  fibrous  coat  of  arteries  wdth  the  non- 
albuminous  textures,  as  cellular  tissue,  cartilage,  &c.  The  ultimate  fibres  of 
he  middle  coat,  viewed  microscopically,  are  smooth,  branched,  and  anastomose 
reticularly,  like  the  fibres  of  involuntary  muscles  : they  present  a remarkably 
clear  dark  outline.]! 

24 


266 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  first  is  the  motion  of  whole  bodies  by  means  of  an  external 
impulse,  the  vis  inertia  of  the  body  being  overcome. 

The  second  is  the  motion  from  attraction  of  one  species  of 
matter  to  itself  or  to  another  species,  as  wholes.  Of  this  kind 
is  gravitation,  perhaps  magnetism  and  electricity,  probably  also 
cohesion. 

The  third  kind  of  motion  is  from  chemical  attraction,  where, 
besides  the  attraction  of  whole  parts,  there  is  an  elective  attraction 
between  the  particles  of  one  kind  of  matter  and  those  of  another, 
as  it  were  drawing  them  out  from  the  general  mass.  This  can 
only  happen  when  suspended  in  a fluid  or  in  the  form  of  vapour,  no 
other  form  admitting  of  the  motion  of  particles  among  themselves. 
Repulsion  produces  a similar  motion  among  the  parts. 

The  fourth  kind  of  motion  is  muscular,  arising  most  probably 
from  construction,  and  a principle  in  action  very  different  from  the 
attractions  in  common  matter. 

This  action  and  the  others  are  equally  unintelligible,  the  general 
effect  alone  being  evident  to  our  senses. 

From  the  effect  in  muscular  motion,  we  should  be  inclined  to  sup- 
pose that  there  is  an  approximation  of  the  parts  in  one  direction, 
which  in  the  whole  produces  a visible  contraction. 

It  is  natural  to  suppose  that  all  muscular  fibres  act  alike  ; that 
every  fibre  in  every  muscle  when  in  action  is  under  exactly  the 
same  circumstances:  therefore  whatever  variety  may  appear  in 
muscular  action,  or  difference  between  theaction  of  different  muscles, 
must  depend  upon  the  various  causes  and  intentions  of  these  actions. 

A muscle  in  action  as  it  contracts  becomes  more  dense  or  hard, 
and  therefore  rijsriorj  we  should  suppose  it  becomes  less,  as  we  can 
form  no  adequate  idea  of  the  same  substance  becoming  firmer  or 
harder  without  either  an  approximation  of  its  parts,  or  an  addition 
of  new  matter  introduced  into  all  its  parts,  or  a particular  position 
of  the  constituent  parts  of  a muscular  fibre,  so  as  to  become  im- 
moveable while  in  that  position. 

One  circumstance,  however,  which  makes  muscular  fibres  firmer 
when  contracted  in  the  living  body  is,  their  always  overcoming 
some  resistance  in  such  contraction,  which  puts  them  more  or  less 
in  the  situation  of  a stretched  cord. 

Take  the  unattached  hairs  which  compose  the  strings  of  the  bow 
of  a fiddle,  and  they  will  feel  pliant  or  soft;  but  when  put  upon 
the  stretch  they  will  feel  much  firmer.  An  elastic  body  also,  as 
India  rubber,  feels  much  firmer  while  stretched  than  when  con- 
tracted and  at  ease,  by  its  natural  elasticity.  A muscular  fibre, 
however,  in  the  state  of  tension  between  the  two  points  is  little  in- 
debted to  this  cause  for  its  firmness,  although  it  will  increase  the 
effect  produced  by  the  position  of  its  component  parts  ; for  a mus- 
cular fibre  unattached  is  very  much  increased  in  hardness  while 
contracted,  as  in  crimped  fish,*  and  in  the  flesh  of  all  animals 

* [Sir  Anthony  Carlisle  found  that  the  contracted  muscles  in  crimped  fish  had 
not  only  acquired  a sensible  rigidity,  but  also  an  increase  of  specific  gravity. 
See  his  ‘ Croonian  Lecture  for  the  year  1804,’  Philos.  Trans.,  1805,  p.  1.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


267 


allowed  to  die  so  gradually  that  the  muscles,  from  the  stimulus  of 
death  taking  place,  contract:  but  a muscle  is  as  firm  and  as  strong 
in  all  its  degrees  of  contraction  as  it  is  in  its  full  contraction,  if  not 
firmer  and  stronger  than  in  its  ultimate;  therefore  cannot  be  called 
contraction.  It  is  its  proximity  of  its  parts  arising  from  that  attrac- 
tion, not  from  the  proximity  of  such  parts  mechanically,  but  at- 
tractively. 

Many  authors  of  authority,  as  well  physiologists  as  others,  have 
attempted  to  explain  the  contraction  of  a muscular  fibre ; but, 
however  ingenious  their  opinions  may  be,  none  of  them  completely 
account  for  any  one  particular,  relative  to  muscular  contraction: 
I shall,  however,  mention  them,  with  the  objections  to  which  they 
are  liable. 

In  the  investigation  of  this  subject  the  following  apparent  altera- 
tion in  the  figure  of  a muscular  fibre  has  been  principally  attended 
to  : When  a muscle  acts,  it  increases  in  thickness,  and  becomes 
visibly  firmer  in  texture,  therefore  each  component  fibre  of  the  mus- 
cle must  be  supposed  to  undergo  the  same  change;  and  many  ex- 
periments have  been  made  to  ascertain  whether  this  increase  of 
thickness  in  a muscular  fibre  is  in  proportion  to  its  decrease  in 
length,  but  hitherto  without  effect:  probably  the  only  method  of 
ascertaining  this  fact  is,  to  determine  whether  a muscle  in  the  state 
of  contraction  is  really  increased  or  diminished  in  its  bulk, 

Haller,  in  his  Elements  of  Physiology,  asks  the  following  ques- 
tions: “Does  a muscle  really  increase  in  bulk  in  its  action?  As 

a muscle,  when  it  acts,  becomes  shorter,  and  swells,  we  may  next 
ask.  Do  these  two  changes,  contraction  and  dilatation,  compensate 
each  other?  that  is.  Is  there  the  same  quantity  of  matter  in  it  at 
both  these  periods  ? Or  does  a muscle  in  action  really  lose  in  its 
size?  or  does  it  srain  in  bulk  what  it  loses  in  length?  Both  sides 
of  the  question  have  had  their  advocates.” 

Borelli,  to  find  out  whether  a muscle  really  had  an  addition  of 
new  matter  in  its  contracted  state,  and  thereby  became  heavier, 
made  the  following  experiment : 

He  placed  a naked  man  upon  a table  suspended  upon  a point, 
which  supported  it  directly  under  his  buttocks,  in  which  situation 
he  was  perfectly  balanced.  He  was  then  desired  to  act  with  the 
muscles  of  the  lower  extremities,  but  he  still  kept  his  balance,  no 
change  taking  place  in  the  equilibrium.  (Borelli,  vol.  ii.,  p.  39.) 

This  experiment  was  made  most  probably  upon  the  supposition 
that  some  additional  matter  was  to  flow  from  the  brain  along  the 
nerves,  or  from  the  heart  along  the  vessels  to  the  muscles  of  the 
extremities,  so  as  to  render  the  upper  part  lighter,  and  the  lower 
part  heavier.  If  it  was  to  come  from  the  brain,  it  was  conceiving 
the  supposed  animal  spirits  to  be  heavier  than  air,  of  all  of  which 
we  are  wholly  ignorant. 

The  celebrated  experiments  of  Goddard,  Glisson,  and  Swam- 
merdam are  quoted,  to  prove  that  muscles  lose  in  their  bulk  while 
in  action.  They  put  a muscle  or  a whole  limb  into  a glass  vessel, 


268 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


and  filled  it  up  with  wafer ; they  then  made  all  the  muscles 
act  at  once  ; or  if  a single  muscle,  they  irritated  the  nerve,  and 
made  it  contract,  during  which  time  they  attended  to  the  motion  in 
the  water,  and  its  rising  or  falling  was  to  determine  whether  the 
size  of  the  muscle  was  increased  or  diminished. 

Swammerdam,  in  trying  this  experiment  with  a single  muscle 
(the  heart  of  a frog),  saw  the  water  sink  in  the  contraction  of  that 
muscle,  and  rise  in  its  relaxation. 

The  result  of  this  experiment  has  been  very  differently  explained. 
Swammerdam  himself  doubted  its  being  conclusive,  believing  the 
air  might  be  compressed  during  the  heart’s  action  ; but  we  have  no 
proof  of  the  presence  of  air  in  a muscle  in  the  simple  state  of  air. 

Boerhaave  and  Sauvages  accounted  for  the  water  descending  by 
the  blood  being  pressed  out  by  the  contraction  of  the  muscle,  which 
blood  was  returned  into  it  by  the  relaxation,  and  raised  the  water. 
This  certainly  would  be  the  case  in  the  experiment  made  upon  a 
whole  limb:  for  we  know,  from  everyday’s  experience,  that  in 
bleedings  from  the  arm  the  blood  is  thrown  out  more  forcibly  while 
the  muscles  are  in  action:  therefore  there  is  less  blood  in  the  vessels 
of  the  limb  w'hen  the  muscles  are  contracted  than  in  a state  of 
relaxation,  and  of  course  the  limb  is  less  in  bulk  at  that  time  than  in 
the  other  : but  when  a single  muscle  or  a whole  animal  is  immersed 
in  water,  whatever  loss  the  muscle  has  in  its  substance  must  be 
gained  by  the  w'ater,  so  that  the  whole  can  neither  be  diminished  nor 
increased. 

Hambergerus  tied  a string  round  a man’s  arm,  and  found  that 
during  the  action  of  the  muscles  it  cut  him  ; he  therefore  thought 
that  muscles  in  action  were  increased  ; but  the  experiment  only 
proved  that  it  became  thicker,  w'hich  is  generally  allowed. 

It  has  been  objected  to  such  experiments,  that  if  a person  acts 
only  with  one  set  of  muscles,  their  opponents  become  stretched  or 
relaxed  in  proportion,  keeping  up  an  equilibrium  in  the  part : as 
antagonizing  muscles,  however,  never  bear  a just  proportion  to  one 
another  in  strength,  it  follows,  that  if  w'e  act  with  the  strongest  set 
of  muscles  the  limb  will  of  course  become  thicker  in  the  proportion 
that  the  strength  of  the  acting  muscles  bears  to  the  strength  of  the 
relaxing  ones,  and  vice  versa. 

To  ascertain  with  as  much  precision  as  possible  whether  a muscle 
really  alters  in  size  or  not  when  contracted,  I repeated  the  experi- 
ments of  Goddard,  Glisson,  and  Swammerdam,  but  in  such  a way 
as  to  have  little  or  no  doubt  what  w-as  the  effect.  I got  a glass 
blown  which  contained  almost  a gallon  ; its  mouth  was  about  three 
inches  over,  to  admit  its  receiving  a pretty  large  muscle,  and  was 
fitted  with  a ground-glass  stopper,  which  was  water-tight,  and  a 
glass  tube  was  fitted  into  this  stopper,  so  as  to  communicate  with 
the  cavity  of  the  glass,  being  at  the  same  time  water-tight.  This 
apparatus  could  be  filled  with  water,  and  have  the  water  stand  at 
any  height  in  the  tube  which  might  be  required,  so  as  to  give  with 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


269 


great  nicety  the  comparative  size  (should  there  be  any  difference), 
of  a muscle  when  contracted  and  when  relaxed,  while  immersed 
in  it. 

The  muscles  best  adapted  for  experiments  of  this  kind  are  those 
which  have  no  antagonists,  for  in  that  case  the  contraction  of  one 
muscle  produces  the  elongation  of  the  other.  The  muscle  should  be 
wholly  detached,  having  neither  origin  nor  insertion,  as  a muscle 
cut  out  of  the  body,  or  cut  from  its  attachment,  as  in  crimped  fish  ; 
those  muscles  however  are  best  which  have  no  natural  attachment, 
as  the  heart. 

In  repeating  such  experiments  it  will  be  hardly  possible  to  have 
the  result  of  two  exactly  the  same,  for  no  two  muscles  will  be 
equally  relaxed  at  the  beginning  of  the  experiment,  nor  will  any 
two  muscles  contract  equally;  but  if  there  is  one  universal 
general  eflect  taking  place  in  all  of  them,  that  general  effect  be- 
comes the  result  of  the  experiment,  and  is  what  is  to  be  at- 
tended to. 

Experiment  1.  I killed  a dog  instantaneously,  and  took  out  the 
heart  as  expeditiously  as  possible,  and  put  it  into  the  glass  filled 
with  water,  and  immediately  after  putting  in  the  stopper  with  the 
glass  tube  fixed  in  it.  I now  observed  the  height  at  which  the  water 
stood  in  the  tube. 

The  heart  had  so  far  lost  its  action  as  not  to  contract  and  relax 
alternately,  having  only  the  power  of  contraction  from  the  stimulus 
of  death,  and  when  put  into  the  water  was  perfectly  relaxed.  It 
was  allowed  to  remain  in  the  water  some  hours ; and  it  was  ob- 
served, that  by  its  apparent  loss  of  bulk  it  had  contracted  con- 
siderably; and  we  also  found  that  the  water  in  the  tube  had 
fallen.*  The  next  thing  to  be  done  was  to  ascertain  how  much 
the  heart  had  lost  in  size,  which  was  known  by  the  quantity 
necessary  to  fill  up  the  glass  to  the  first  height,  which  was  sixteen 
grains. 

The  size  of  the  heart  was  equal  to  two  ounces  six  drachms, 
and  thirty-eight  grains  of  water,  that  is,  1328  grains,  so  that  the 
contracted  state  was  to  the  relaxed  as  82,  to  83,  or  Vsd.  part  of 
the  whole. 

Experiment  2.  I took  the  heart  of  a sheep,  whose  size  was  equal 
to  13  ounces  or  104  drachms  of  water;  it  lost  in  contraction  1 
drachm ; so  that  the  contracted  state  was  to  the  relaxed  as  T^cth 
part  of  the  whole. 

Experiment  3.  I took  a live  eel,  w'hich  was  gutted,  to  remove 
as  much  as  possible  everything  not  muscular,  and  then  crimped,  to 
destroy  the  attachment  of  most  of  the  muscles.  The  eel  was  equal 
to  14  ounces  and  133  grains,  or  6853  grains  of  water,  and  it  lost 
in  contraction  39  grains,  or  xith  part  of  the  whole.f 

* It  is  to  be  observed  that  the  water  was  kept  in  the  same  degree  of  heat  through 
the  whole  of  the  experiment. 

I [In  tlie  experiments  above  detailed  Hunter  drew  his  conclusions,  as  to  the 
change  of  bulk  in  a muscle  during  contraction,  from  the  effects  observed  in  the  level 

24* 


270 


HUNTER  ON  THE  ANIMAL  CECONOMT. 


As  this  animal  was  composed  of  muscles,  bones,  &c.,  some 
allowance  is  to  be  made  for  these  parts,  which  will  account  in 
some  measure  for  the  diflerence  in  the  result  between  this  and  the 
hearts,  although  in  the  experiments  on  tlie  hearts  there  is  a con- 
siderable diflerence  between  the  two,  arising  from  the  reasons 
above  mentioned. 

It  appears,  however,  upon  the  whole,  that  a muscle  loses  more 
of  its  length  than  it  gains  in  thickness,  unless  the  apparent  diflerence 
arises  from  an  universal  approximation  of  all  its  parts. 

As  a muscle  loses  in  its  general  size  by  the  contraction  of  the 
length  of  its  fibres,  we  cannot  suppose  that  contraction  to  arise  from 
the  introduction  of  additional  matter  into  those  fibres;  therefore 
the  opinions  that  a muscular  fibre  is  a hollow  tube  from  end  to  end, 
or  a chain  of  cells  of  various  shapes,  either  rhomboidal  or  circular, 
according  to  the  ideas  of  the  authors  of  such  opinions,  and  these 
cells  being  filled  with  foreign  matter,  must  fall  to  the  ground  in- 

of  the  surrounding  fluid,  after  the  last  contraction  of  the  part  or  ‘ rigor  mortis.’  In 
Mr.  Mayo’s  well-known  experiment,  which  is  similar  to  the  first  of  Hunter’s', 
the  ordinary  contractions  of  the  ventricles  of  a dog’s  heart,  alternating  with  re- 
laxations of  the  same  parts,  produced  no  perceptible  change  in  the  level  of  the 
water  in  the  tube.a  In  comparing  the  above  experiments,  one  cannot  fail  to  be 
struck  with  the  period  during  which  the  muscular  contractions  of  the  dog’s  heart 
continued.  But  as  Hunter  killed  his  dog  instantaneously,  it  was  probably  by  some 
sudden  concussion  or  injury  to  the  brain,  when  the  action  of  the  heart  would  be 
arrested,  and  the  last  contraction  only  would  be  witnessed,  notwithstanding  the 
expedition  wfith  which  it  was  taken  out.  In  Mr.  Mayo’s  experiment  the  dog 
was  killed  by  hanging,  and  the  ventricles  of  the  heart  continued  alternately  to 
contract  and  dilate  for  a considerable  time.  Barzolotti,  Prevost  and  Dumas,  wLo 
performed  similar  experiments  on  smaller  portions  of  flesh,  also  found  no  change 
of  level  to  take  place  in  the  surrounding  fluid  during  the  contraction  of  the  muscle. 
Gruithuisen  and  Ermann,'>  on  the  contrary,  observed,  like  Hunter,  a slight  change 
in  the  bulk  of  the  muscle  during  contraction.  Ermann  introduced  into  a glass 
vessel  the  posterior  half  of  an  eel,  the  intestines  being  removed.  A metal  wire 
was  inserted  into  the  spinal  marrow,  and  a second  into  the  flesh,  and  these  were 
directed  so  as  to  be  brought  into  communication  with  the  pole  of  a galvanic  bat- 
tery. The  vessel  was  then  filled  with  water,  so  that  a narrow  tube,  in  which  the 
apparatus  ended  above,  was  filled.  In  completing  the  chain,  and  during  the  con- 
traction of  the  muscles,  the  wmter  fell  in  the  tube  four  or  five  lines,  and  again 
rose  to  the  opening,  when  the  muscle  relaxed. 

If,  however,  the  muscular  fibre,  which  is  generally  admitted  to  have  increased 
in  density,  and,  according  to  the  experiments  of  Sir  Anthony  Carlisle,  in  specific 
gravity,  during  contraction,  has  really  diminished  in  bulk,  the  difference  is  so 
trifling  that  we  can  hardly  avail  ourselves  of  it  in  elucidating  the  nature  of  mus- 
cular contraction.] 

* [It  is  now  generally  admitted  by  microscopical  observers  that  the  ultimate 
muscular  fibre  is  solid.  The  voluntary  muscular  fibres  (‘  secondary  fibres’  of 
Prevost  and  Dumas,  ‘ultimate  fasciculi’  of  Miiller,)  in  the  vertebrate  classes, 
and  those  of  insects,  arachnidans,  crustaceans,  and  cirripeds,  present  a micro- 
scopical character  which  distinguishes  them  from  every  other  animal  tissue:  it 
consists  of  close-set,  parallel,  transverse,  or  slightly  oblique  and  sometimes  slight- 
ly curved  stria;.  The  fibres  which  present  these  strise  are  divisible  into  component 
fibrillae,  which  have  a knotted  or  beaded  structure ; this  I have  myself  observed 


a Anatomical  and  Physiological  Commentaries,  vol.  i.,  p.  12. 
[Gilbert's  Annalen,  40.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


271 


deed,  this  idea  of  a muscular  fibre  being  a chain  of  cells  does  not 
account  for  any  one  phenomenon  attending  muscular  motion,  and 
is  directly  contradicted  by  two  circumstances  attending  muscular 
contraction:  the  first  of  these  is  the  muscle  becoming  rather  less 
than  larger  in  its  contraction,  which  is  just  contrary  to  w'hat  must 
have  happened  if  the  contraction  had  been  owing  to  that  cause; 
the  second  is,  that  a muscle  is  capable  of  contracting  much  more 
than  one-third  of  its  length,  and  indeed,  as  far  as  we  yet  know, 
having  no  limitation,  which  could  not  possibly  happen  if  they  were 
tubes  capable  of  receiving  foreign  matter  into  their  cavities;  for 
according  to  that  idea,  a muscular  fibre  should  become  thicker  in 
its  contraction  in  proportion  as  the  diameter  of  a sphere  is  greater 
than  that  of  a cylinder  of  the  same  area,  which  would  be  an  im- 
mense increase. 

Although  a muscle  becomes  on  the  W'hole  somewhat  less  in  its 
contraction,  and  has  its  ends  brought  considerably  nearer  together, 
yet  it  cannot  be  called  attraction,  for  there  is  nearly  the  same 
reason  for  supposing  a lateral  repulsion,  as  the  muscle  swells  out 
laterally  almost  as  much  as  it  contracts  in  the  other  direction. 

I do  suppose  that  a muscular  fibre  is  not  one  uniform  body  from 
end  to  end,  but  is  made  up  of  parts,  which  may  be  called  the  com- 
ponent parts  of  a muscular  fibre;  and  I am  apt  to  suppose  that  a 
change  takes  place  in  the  position  of  those  parts,  during  contrac- 
tion, and  this  alteration  diminishes  the  extent  of  those  parts  in  one 
direction  while  it  is  increasing  them  in  the  other,  although  from 
the  experiments  it  appears  not  to  be  in  the  same  proportion ; but 
what  that  alteration  is  I shall  not  pretend  to  determine.*= 

in  the  human  voluntary  fibre,  and  in  that  of  the  mole-cricket.  Some  physiologists 
suppose  that  the  transverse  striae  result  from  the  lateral  apposition  of  the  knots 
on  the  parallel  fibrillee.  The  muscular  fibres  of  the  mollusca  and  radiata,  and 
the  involuntary  muscular  fibres  of  the  vertebrata,  with  the  exception  of  those 
developed  in  the  vascular  layer  of  the  germ  disc,  as  the  fibres  of  the  heart,  do  not 
present  the  striated  character.] 

* [According  to  the  observations  of  Hales  (^Ilasmasiatics,  p.  59),  and  ofPrevost 
and  Dumas  (Magendie,  Journal  de  Fhysiologie,  iii.,  p.  301),  the  change  in  the 
muscular  fibre,  at  the  moment  of  contraction,  is  from  a straight  to  a zigzag  line  : 
the  observation  has  been  generally  made  on  the  rectilinear  parallel  fibres  of  one  of 
the  thin  abdominal  muscles  (the  rectus)  of  a young  frog,  stimulated  to  contract 
while  under  the  microscope;  and  the  conclusion  is  admitted  as  an  established 
fact  in  the  most  recent  works  on  physiology.  I have  been  led  to  doubt  this  fact, 
from  observing  the  contraction  of  the  muscular  fibres  in  small  Filarise  (such  as 
commonly  infest  the  abdominal  cavity  of  the  cod),  and  more  especially  from 
observing  the  contraction  of  the  retractor  muscles  of  the  tentacles  of  a species  of 
Vesicularia  of  Vaughan  Thompson,  a compound  polype-like  animal,  which,  under 
the  guise  of  a Sertularia  manifests  a much  higher  type  of  organization.  Here 
each  separate  fibre  of  the  retractor  muscles  is  seen  with  great  distinctness,  and  is 
characterized  by  a single  knot  or  swelling  in  the  middle.  In  the  act  of  retracting 
the  tentacles  the  fibres  become  shorter  and  thicker,  especially  at  the  central  knot, 
but  do  not  fall  out  of  the  straight  line.  After  the  retraction  has  been  effected, 
the  fibres  fall  into  a wavy  or  zigzag  position : but  this  is  characteristic  of  their 
state  of  relaxation  under  the  circumstances  which  bring  their  two  attached  ex- 
tremities nearer  each  other.  In  like  manner,  in  the  parallel  longitudinal  fibres 
of  the  Filaria,  it  is  most  evident  that,  at  the  moment  of  contraction,  they  become 


272 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


Muscles  have  a disposition  to  throw  themselves  into  wrinkles  or 
corrugations  when  not  in  action,  and  when  the  position  of  the  part 
moved  by  these  muscles  is  such  as  allows  the  muscle  to  be  in  its 
shortest  state,  as  in  the  biceps-flexor-cubiti  after  having  bent  the 
arm.  If  it  is  kept  in  that  position  by  any  other  power,  the  biceps 
will  leave  acting  and  fall  into  wrinkles,  adapting  itself  to  the  short 
distance  between  its  origin  and  insertion;  so  that  these  wrinkles 
are  a kind  of  substitute  for  the  contraction  that  was  in  the  muscle. 

The  greatest  strength  in  a muscle  while  in  action  is  probably 
when  it  is  half  contracted,  as  we  find  that  in  all  great  exertions  of 
muscular  strength,  where  ultimate  actions  are  to  take  place,  the 
muscles  employed  are  never  allowed  to  relax  their  full  relaxation, 
or  contract  to  their  full  contraction. 

When  a man  walks  with  a heavy  load  his  knees  are  a little  bent, 
even  of  the  leg  he  stands  upon,  which  supports  the  whole  while  he 
is  moving  the  other.  The  same  thing  takes  places  if  he  is  weary  ; 
but  if  strong  and  full  of  activity  his  perpendicular  joints  may  be 
kept  pretty  straight. 

The  same  thing  also  takes  place  in  old  people  from  the  same 
cause;  for  as  they  become  naturally  weak,  they  become,  like  the 
strong,  loaded  with  a heavy  burden,  therefore  take  on  the  same 
modes  of  action  : the  knees  are  never  straightened,  the  back  bent 
forwards,  and  all  the  parts  that  are  constantly  in  the  action  of  sup- 
port are  all  getting  out  of  the  perpendicular,  in  which  perpendicular 
state,  although  they  might  be  mechanically  stronger,  yet  they  are 
muscularly  weaker,  therefore  get  into  that  position  in  which  the 
muscles  can  act  with  the  greatest  advantage. 

The  relaxcrs,  which  become  the  sustainers  of  the  muscles  in 
action,  never  allow  themselves  to  relax  to  their  full  extent  while 
the  contractors  are  carrying  on  the  motion  of  a part,  as  it  would 
produce  weakness. 

The  relaxation  of  muscles  when  contracted  involuntarily,  but 
from  obnoxious  stimuli,  will  not  relax  by  the  will;  nothing  but  a 
counter-stimulus  of  necessity  can,  and  even  that  wdth  difficulty. 
For  instance,  if  we  attempt  to  breathe  obnoxious  air,  or  if  anything 
touches  the  glottis,  it  immediately  shuts,  and  it  is  out  of  the  power 
of  the  will  to  relax  it ; but  the  stimlus  of  the  necessity  of  breathing 
brings  it  to  again.  A muscle  that  has  but  one  determined  use,  or 
rather  a muscle  that  has  but  one  point  of  orgin  and  one  point  of 
insertion,  always  acts  w'holly  when  put  into  action,  so  as  to  bring 

shorter  and  thicker,  hut  do  not  alter  their  rectilinear  position  until  the  action 
has  ceased,  when  they  fall,  like  the  parallel  nervous  chord,  into  zigzag  folds, 
which  continue  until  effaced  by  the  restoration  of  the  part  to  its  usual  length 
through  the  action  of  the  exterior  transverse  fibres. 

On  relating  these  observations  to  my  friend  Dr.  Allen  Thompson,  he  informed 
me  that  on  repeating  the  experiment  of  Hales  and  Prevost  on  the  frog,  he  had 
observed  single  fibres  continuing  in  contraction,  and  being  simply  shortened,  and 
not  falling  into  the  zigzag  plicae  ; and  he  was  led  to  suspect,  from  this  and  other 
appearances,  that  the  zigzag  arrangement  was  not  produced  till  after  the  act  of 
contraction  had  ceased.] 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


273 


about  its  etFect  on  the  part  of  insertion  ; I believe  never  one  part 
of  the  muscle  only,  or  only  a few  of  its  fibres,  but  the  whole.  This 
is  not  the  case  with  muscles  whose  origin  is  broad  and  its  insertion 
narrow,  whose  insertion  is  broad  and  its  origin  broad,  or  whose 
origin  is  narrow  and  insertion  broad. 

But  in  spasm  in  a muscle  a very  few  fibres  may  be  seen  to  act; 
in  short,  any  number  may  act,  as  it  is  not  motion  of  the  part  that 
is  the  intent  of  the  action. 


Relaxation. 

Muscular  fibres  have  a greater  power  of  contraction  than  what 
is  barely  sufficient  for  the  extent  of  the  motion  of  the  parts  upon 
which  they  are  designed  to  act.  This  is  illustrated  in  the  shell-fish 
called  bivalve,  for  the  muscle  in  that  fish  brings  the  two  shells  to- 
gether; but  if  one  of  the  shells  be  broken,  so  as  to  allow  of  a 
nearer  approximation  of  the  two  insertions  of  the  muscle,  we  find 
that  they  are  brought  nearer.  It  is  also  evident  where  the  tendo- 
Achillis  or  patella  is  broken,  for  when  that  happens  the  fibres  are 
allowed  to  contract  to  the  full  extent  of  their  original  contraction, 
and  the  parts  heal  in  that  position;  in  such  cases  the  muscle  is  be- 
come shorter  the  whole  length  of  its  natural  contraction,  and  the 
tendon  is  become  so  much  longer;  and  in  this  case,  if  the  muscle 
was  not  possessed  of  a greater  power  of  contraction  than  was  be- 
fore made  use  of,  or  did  not  acquire  a greater  power,  no  motion 
could  now  take  place,  whereas  we  find  the  ultimate  quantity  of 
motion  produced. 

If  the  power  of  contraction  was  limited  to  the  quantity  produced 
in  a straight  muscle,  the  same  kind  of  fibres,  when  forming  sphincter 
muscles,  could  not  answer  the  intended  purposes,  as  a greater  power 
of  contraction  is  required. 

That  the  same  length  of  fibre  is  not  absolutely  necessary  to  pro- 
duce in  all  cases  the  same  effect,  is  strongly  evinced,  by  the  fibres 
of  the  gastrocnemius  muscle  in  the  African  negro,  being  shorter 
than  in  the  European,  yet  producing  exactly  the  same  quantity  of 
motion  in  the  joints  which  they  move.  This  takes  place  univer- 
sally in  the  Africans,  and  now  and  then  is  met  with  in  men  of  other 
nations. 

This  difference  in  the  length  of  muscular  fibres  is  a principal 
reason  of  the  difference  in  the  outline  of  most  men  from  one  another ; 
it  is  at  least  a secondary  cause,  and  should  be  particularly  attended 
to  by  painters  and  sculptors,  as  it  is  a distinguishing  mark  between 
original  nations. 

The  contraction  of  a muscular  fibre  is  produced  by  the  following 
causes : simple  mechanical  pressure,  as  touch,  the  pricking  of  a 
pin,  &c. ; simple  impression  on  another  part  which  acts  upon  this 
by  sympathy. 


274 


HUNTER  ON  THE  ANIMAL  OECONOMY, 


It  is  also  produced  by  properties  of  matter  which  are  not  me- 
chanical, as  the  essential  oils,  salts,  acids,  &c. ; by  affections  of  the 
mind  and  intentions  of  the  will  by  means  of  the  nerves  ; by  the 
circumstances  of  the  body  itself  at  the  time,  as  want,  repletion,  &c. ; 
and  even  by  death  itself. 

An  animal  that  dies  so  slowly  as  to  allow  the  stimulus  of  death 
to  be  felt  by  its  muscles,  has  those  muscles  so  contracted  as  to 
become  stiff;  whether  this  contraction  is  equal  to  the  greatest 
power  of  contraction  of  the  same  muscle,  in  such  a position  of  the 
parts  in  the  living  body,  I do  not  know. 

In  order,  however,  to  ascertain  how  much  a common  muscle 
contracts  from  the  stimulus  of  death,  I cut  out  a muscle  from  a 
horse  just  after  it  was  killed,  and  found  that  in  the  action  of  death 
it  had  contracted  one-third,  and  that  the  muscle  so  contracted  had 
become  one-fourth  thicker  in  its  diameter,  a proportion  I believe  it 
would  have  kept  in  the  living  body;  also  the  same  muscle,  when 
stretched,  or  when  put  into  what  in  the  living  body  may  be  called 
the  relaxed  state,  did  not  again  contract. 

The  contraction  of  muscles  from  the  stimulus  of  death  is  a 
stronger  contraction  than  the  attraction  of  cohesion  of  the  muscles 
themselves  ; therefore  when  a muscle  so  contracted  is  attempted 
to  be  elongated  it  generally  tears  asunder;  but  this  is  not  always 
the  case,  it  only  takes  place  under  certain  circumstances ; it  is 
with  respect  to  the  muscle  itself  in  proportion  to  the  power  of  con- 
traction of  the  muscle,  for  we  find  it  takes  place  much  oftener  in 
those  that  die  of  violent  deaths,  especially  when  they  die  of  strong 
convulsions  ; it  seldom  or  ever  takes  place  in  those  which  die  of  a 
disease  of  some  standing,  for  in  them  the  muscles  have  lost  in  some 
degree  their  absolute  power  of  contraction ; as  also  the  disease 
may  be  such  as  has  in  some  degree  destroyed  the  stimulus  of  death 
upon  the  muscles,  so  that  their  contraction  will  be  less,  although 
their  power  may  be  pretty  strong. 

It  would  appear  from  the  above  that  muscular  contraction  is  not 
simply  an  approximation  of  the  parts  of  which  a muscular  fibre  is 
composed. 

What  the  difierence  is  in  a muscular  fibre  between  its  relaxed 
state  and  the  contracted,  perhaps  may  nev^er  be  known. 

Relaxation  would  appear  to  be  a natural  consequence  of  the  con- 
traction having  answered  its  end  or  fulfilled  its  purpose;  or  it  may 
be  supposed  to  have  got  rid  of  its  stimulus  by  this  action,  the  stimu- 
lus ceasing  to  have  power  when  the  action  has  taken  place  ; there- 
fore relaxation  naturally  occurs  till  excited  to  action  by  another 
sitmulus,  of  which  it  is  susceptible. 

Relaxation  might  be  supposed  to  be  a simple  cessation  of  action, 
but  I think  it  is  not;  it  appears  to  me  to  be  a power  as  much  de- 
pending on  life  as  contraction  ; for  if  it  was  simply  a cessation 
of  action,  muscles  would  become  relaxed  that  had  contracted  by 
the  stimulus  of  death  whenever  absolute  death  took  place,  which  is 
not  the  case ; on  the  contrary,  it  takes  probably  as  much  force  to 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


27  r> 

overcome  this  contraction  as  the  same  muscles  would  have  done 
when  acting  with  all  the  power  of  the  will  in  the  living  body. 

From  the  violence  necessary  for  the  elongation  of  a muscular 
fibre  after  death,  it  would  appear  that  the  position  of  the  component 
parts  of  a fibre  in  any  degree  of  contraction  is  such  as  requires  force 
to  alter  or  remove  it,  and,  whatever  that  position  is,  it  can  be  in 
part  drawn  out  as  if  only  in  part  contracted,  or  wholly  drawn  out ; 
and  in  this  operation  of  drawing  out  or  relaxing  a muscular  fibre 
after  death,  we  may  observe  there  is  a recoil  or  reaction  in  a certain 
degree  when  the  elongating  force  is  removed,  becoming  in  this 
respect  similar  to  elasticity.  This  recoil,  however,  is  not  extensive, 
although  it  takes  place  in  every  degree  of  relaxation,  from  the  most 
contracted  state  to  the  almost  totally  relaxed  state. 

I first  observed  this  recoil  in  a man  who  died  in  convulsions  in 
St.  George’s  Hospital,  from  a fever,  attended  with  delirium,  which 
was  brought  on  by  a hurt  on  his  arm,  which  inflamed  considerably. 
A few  hours  after  death  his  muscles  were  stifier  than  usual,  and 
extremely  well  marked  through  the  skin,  which  induced  me  to  make 
the  following  experiment  on  the  relaxation  of  muscles.  I laid  bare 
the  rectus  muscle  of  the  thigh,  and  separated  it  from  the  other  mus- 
cles without  stretching  it;  I then  passed  a thread  behind  it  and 
inclosed  the  muscle,  and  cut  the  thread  off  where  the  ends  met. 
Upon  bending  the  knee  the  muscle  was  stretched,  and  I found  that 
the  ends  of  the  thread  were  lapped  over  each  other.  Upon  mea- 
suring the  difference  it  was  one-eighth  of  an  inch  diminished  from 
what  it  was  in  the  contracted  state. 

I was  much  surprised  by  a considerable  degree  of  contraction  in 
the  muscles,  similar  to  elasticity,  for  they  evidently  contracted  a 
good  deal  after  being  stretched.  I suspected  that  this  had  arisen 
from  some  remains  of  life,  and  therefore  waited  till  the  next  day, 
when  the  same  thing  happened. 

If,  in  stretching  a contracted  muscle  after  death,  the  fibres  are 
not  drawn  out  beyond  this  power  of  recoil,  the  whole  contraction 
of  the  muscle  (whatever  quantity  it  is)  continues  the  same;  but  if 
the  muscle  is  drawn  out  further  than  this  power  of  recoil,  then  the 
muscle  becomes  so  far  relaxed,  but  no  further ; for  instance,  if  the 
recoil  is  the  one-twelfth  of  an  inch,  and  the  muscle  is  only  stretched 
so  far,  then  the  muscle  will  contract  again  one-twelfth  of  an  inch  ; 
but  if  it  is  stretched  one-sixth  of  an  inch,  then  it  wall  still  only  recoil 
one-twelfth,  the  other  one-twelfth  being  the  absolute  relaxation  of 
the  muscle. 

From  all  that  is  mentioned  above,  I think  it  will  appear  that  re- 
laxation of  a muscular  fibre  depends  upon  life  as  much  as  the  con- 
traction, neither  the  one  nor  the  other  being  produced  after  death 
by  any  property  in  the  muscle. 

The  causes  of  relaxation  are  few  ; the  will  is  perhaps  the  princi- 
pal one,  although  not  in  all  muscles.  Emotion  of  the  mind  would 
appear  to  have  a power  of  stopping  the  action  of  the  heart,  but  is 
perhaps  only  hindering  a new  contraction. 


276 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  contraction  and  relaxation  of  a muscle  are  always  adapting 
themselves  to  the  motions  of  the  parts  on  which  they  are  to  act, 
so  that  if  a joint  continues  bent  for  sometime  the  muscle  will  retain 
it  in  that  situation,  and  any  extension  of  that  joint  will  put  the  mus- 
cular fibres  on  the  stretch.  This  is  not,  as  has  been  supposed,  a 
contraction  of  the  tendon,  but  a contraction  in  the  muscle,  to  adapt 
it  to  the  remaining  motion  in  the  joint,  this  half  contracted  state 
becoming  now  the  state  of  relaxation  from  which  the  muscle  is  in 
future  to  produce  its  action.  The  point  of  relaxation  of  a muscle, 
therefore,  is  always  the  extent  of  motion  in  the  joint,  and  the  quantity 
of  contraction  of  a muscle  is  always  equal  to  the  full  motion  of  the 
joint  on  which  it  acts,  and  if  the  joint  loses  part  of  its  motion  the 
muscle  also  loses  a proportionable  degree  of  contraction,  so  as  still 
to  be  adapted  to  it. 

Muscles,  however,  so  contracted,  may  be  gradually  stretched  to 
their  original  length,  and  recover  their  original  action,  as  the  biceps- 
flexor-cubiti  after  inflammations,  and  abscesses  in  the  arm. 

Muscles  may  be  also  stretched  beyond  their  original  length,  and 
still  retain  their  use,  as  those  of  the  belly  in  dropsies. 

These  circumstances  prove  that  accidents  to  the  body  are  pro- 
vided against  in  its  construction ; for  if  the  muscles  remained  in  the 
half-bent  state  in  the  cases  above  mentioned,  the  length  of  muscle 
would  be  too  great  for  the  quantity  of  motion,  and  the  first  part  of 
its  action  would  produce  no  effect  upon  the  joint. 


CROONIAN  LECTURE  ON  MUSCULAR  MOTION,  No.  VI. 

FOR  THE  YEAR  1782. 

[Read  before  the  Royal  Society  June  13th,  by  Mr.  John  Hunter,  F.R.S.] 

An  inquiry  how  far,  and  in  what  instances,  the  density  or  firmness  of 
a Muscle  contributes  to  its  strength. 

In  comparative  experiments  respecting  animals,  where  the  actions 
of  life  are  attempted  to  be  imitated  in  the  dead  body,  we  should 
attend  to  every  circumstance  and  see  whether  there  is  really  any 
kind  of  similarity  in  the  experiment.  But,  where  life  is  absolutely 
necessary  for  the  action,  on  one  side,  and  the  action  is  imitated  only 
so  far  as  regards  the  mechanical  mode  of  performing  it,  the  resem- 
blance between  the  vital  action  and  the  experiment  is  in  reality 
very  remote. 

To  suppose  that  the  action  of  a muscle  should  be  equal,  more  or 
less,  with  its  mechanical  strength  when  dead  is  absurd,  because  they 
bear  no  analogy.  The  action  of  a muscle  is  as  unlike  its  mechanical 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


277 


resistance  as  the  effects  of  the  irritability  of  a living  body  upon 
impression  is  like  the  mechanical  effects  of  the  same  impression; 
the  mechanical  effects  being  the  same  in  the  living  as  the  dead. 

The  action  of  a muscle  is  stronger  than  its  mechanical  resistance 
in  the  dead  body;  that  is,  its  power  of  contraction  is  greater  than 
the  attraction  of  the  cohesion  of  its  fibres. 

These  facts  can  only  be  ascertained  by  experiments  on  the  power 
in  the  living  body,  opposing  them  with  the  resistance  in  the  dead  ; 
but  as  a muscle  is  in  very  different  states  in  contraction  and  relaxa- 
tion, even  in  the  living  body,  and  as  the  experiment  is  opposing 
contraction  to  the  state  of  relaxation,  the  experiment  is  not  con- 
clusive: it  does  not  prove  what  it  is  meant  to  prove. 

The  subject  can  and  should  be  viewed  in  several  lights.  A 
muscle  is  first  to  be  considered  in  two  points  of  view ; the  relaxed 
state,  where  it  is  only  united  by  the  common  attraction  of  cohesion 
of  that  muscle,  and  is  probably  as  mechanically  strong  in  the  dead 
as  the  living;  but  they  may  be  considered  in  the  contracted  state 
both  in  the  dead  and  the  living,  for  although  a muscle  does  not  con- 
tract after  death,  yet  it  often  contracts  in  the  act  of  dying ; and 
death  does  not  produce  a relaxation,  therefore  it  is  to  be  presumed 
that  the  position  of  the  parts  of  the  muscle  so  contracted  remains  in 
the  same  state,  and  therefore  such  muscle  affords  an  opportunity  of 
making  comparative  experiments  between  it  and  one  in  the  living 
body  so  contracted. 

How  far  the  same  muscles  in  the  dead  body,  when  fully  con- 
tracted, could  be  relaxed  by  the  same  force  as  when  in  the  living 
state,  I do  not  know.  It  is  certain  that  a muscle  in  health,  and 
which  feels  the  stimulus  of  death  strongly,  contracts  with  consider- 
able force,  and  requires  a considerable  power  to  overcome  it; 
therefore  the  relaxation  of  a muscle,  voluntarily'  contracted,  must 
always  be  an  act  of  the  mind,  or  a cessation  of  action  of  the  mind 
upon  that  muscle.  But  when  a muscle  takes  on  an  action  without 
the  mind,  either  in  diseases,  as  the  involuntary  actions  of  voluntary 
muscles,  or  by  the  stimulus  of  death  (the  immediate  cause  of  action 
being,  I conceive,  the  same  in  both),  then  a relaxation  from  the 
mind  cannot  take  place  in  either,  because  the  mind  had  nothing  to 
do  with  the  first,  and  it  did  not  exist  in  the  second.  So  that  those 
involuntary  actions  of  voluntary  muscles  ari.sc  from  a stimulus  in- 
dependent of  the  will,  and  in  those  whei-e  it  goes  off  it  is  because 
that  stimulus  can  cease,  and  the  part  being  alive  a relaxation  can 
ensue ; whereas  in  death  a relaxation  cannot  ensue,  because  a ces- 
sation of  the  stimulus  cannot  ensue,  that  cessation  being  an  act  of 
the  living  body. 

To  oppose  an  experiment  on  muscles  in  the  dead  body  with  one 
in  the  living,  the  muscles  should  be  always  in  similar  states,  for  a 
muscle  contracted  is  thicker  than  natural,  and  therefore  stronger  in 
its  transverse  direction;  and  if  when  in  a contracted  state  the  par- 
ticles of  which  it  is  composed  are  really  brought  nearer  to  each 
other,  then  it  should  be  doubly  strong,  viz.,  in  proportion  to  its  in- 

25 


278 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


creased  size  and  closer  approximation  of  its  particles.  But  as  the 
slate  of  a muscle  in  contraction  is  totally  ditierent  from  its  natural 
state,  or  that  slate  which  constitutes  the  natural  structure  of  a 
muscle,  no  comparative  experiments  can  be  made  which  can  explain 
anything. 

It  is  evident  from  observation,  that  in  the  construction  of  a 
muscular  fibre  it  was  not  necessary  that  they  should  be  all  of  equal 
density,  for  we  find  some  fibres  denser  than  others.  We  find  this 
difterence  in  the  difi’erent  tribes  of  animals;  in  some  the  fibres  are 
extremely  soft,  while  in  others  they  are  very  firm. 

The  firm  fibre  is  found  in  the  more  perfect  animals,  called  quad- 
rupeds, especially  when  full-grown;  and  this  difierence  of  density 
of  muscular  fibres  would  appear  to  be  in  a pretty  regular  gradation 
from  the  most  imperfect  to  the  most  perfect,  from  the  muscles  of 
the  medusa  to  those  of  the  full-grown  quadruped. 

We  may  also  observe  that  the  first  rudiments  of  every  animal 
are  extremely  soft,  and  even  the  rudiments  of  the  more  perfect  are 
similar  to  the  full-grown  imperfect,  and  as  they  advance  in  growth 
they  become  firm.er  and  firmer  in  texture. 

It  may  likewise  be  observed  that  there  is  a very  considerable 
difierence  in  the  densities  of  the  muscles  in  some  of  those  animals 
that  are  of  distinct  sexes,  the  male  (probably  in  most)  having  by 
much  the  densest  muscles;  and  the  muscles  of  the  same  animal, 
whether  perfect  or  imperfect,  are  not  of  equal  densities,  some  being 
denser  than  others. 

This  arises  from  two  causes, — one  natural,  growing  up  with  the 
animal,  the  other  acquired  by  frequent  action. 

This  difierence  in  density  of  the  muscular  fibres  in  different  ani- 
mals, and  in  the  same  animal  at  difi’erent  ages,  in  different  sexes  of 
the  same  species,  and  even  in  the  same  sex,  also  the  increased  density 
arising  from  action,  must  answer  some  material  purpose,  and,  from 
every  observation,  it  would  appear  to  produce  strength  or  power 
in  the  contraction  of  the  muscular  fibre. 

From  every  circumstance  attending  muscular  contraction,  it  is 
obvious  that  those  muscles  employed  in,  or  intended  for  the  strongest 
actions,  are  the  firmest  in  texture  of  any  animal  body,  at  least  from 
many  circumstances  it  is  natural  to  su[)pose  so  ; that  they  are  the 
strongest  would  appear  from  the  situation  in  which  the  firmest  mus- 
cles are  placed,  for  where  the  strongest  actions  are  found  in  the 
living  body,  there  we  find  the  firmest  muscles  after  death. 

There  are  two  causes  for  this  situation  of  the  firm  or  strong 
muscles  ; the  first  is  an  original  or  natural  one,  a principle  in  the 
animal  oeconomy,  depending  upon  the  natural  growth  of  the  animal 
as  much  as  the  formiation  of  a leg  or  any  other  part.  The  second 
is  action. 

If  we  lake  a general  view  of  the  first  or  natural  cause,  we  shall 
see  from  these  general  observations  where  we  are  to  expect  the 
strongest,  and  of  course  the  hardest,  muscles  in  any  given  animal 
whose  mode  of  action  is  known. 


CKOONIAN  LECTURES  ON  MUSCULAR  MOTION. 


279 


In  animals  which  have  progressive  motion  it  will  generally,  if 
not  always,  be  found  that  this  action  will  be  one  of  their  greatest, 
because  the  parts  intended  for  progressive  motion  bear  a small 
proportion  to  the  whole  animal,  which  they  are  obliged  to  move  ; 
whereas,  every  other  part  has  its  peculiar  muscle,  and  the  muscle 
is  only  obliged  to  move  that  one  part,  which  is  small  in  proportion 
to  the  others. 

Another  actionwhich  manyanimals  are  endowed  with,  and  which 
requires  very  considerable  strength,  is  fighting ; this  is  an  action 
which  always  requires  great  powers  in  the  muscles,  because  it  is 
an  action  in  a part  which  is  to  overcome  the  whole  strength  and 
weight  of  its  antagonist,  which  is  more  than  the  natural  weight  of 
the  same  muscle,  or  the  resistance  of  the  same  muscle,  or  the  resist- 
ance of  any  muscle  in  the  same  body. 

Another  partial  cause  of  strength  in  some  animals  is  for 
catching  their  prey,  which  is  to  overcome  a resistance  consider- 
ably beyond  the  motion  of  the  part  itself  which  is  to  perform  the 
action. 

If  such  parts  of  animals  as  are  adapted  for  progressive  motion, 
for  fighting,  or  for  catching  prey,  require  the  greatest  strength  in 
the  muscle  adapted  for  such  purposes,  and  if  we  find  that  such  parts 
as  are  endowed  with  the  firmest  muscles  are  strongest,  where  all 
those  purposes  are  united  in  the  same  part  in  any  one  animal,  we 
must  find  there  the  greatest  strength,  and  of  course  the  firmest  of 
all  the  muscles  in  the  body,  especially  if  every  one  of  these  actions 
is  considerable  or  violent. 

Thus,  then,  we  find  the  muscles  in  the  arm  of  a lion  where  all 
these  three  purposes  are  performed,  are  extremely  firm  in  texture, 
and  we  must  suppose  are  also  exceedingly  strong.  The  muscles  of 
the  thigh  of  a fighting-cock  are  employed  in  fighting  and  progres- 
sive motion,  and  are  extremely  firm. 

The  muscle  which  has  the  greatest  resistance  in  an  animal  body 
to  overcome  is  the  heart,  especially  in  quadrupeds, and  thisis  perhaps 
the  firmest  in  the  body,  being  even  firmer  than  those  which  have  the 
above-mentioned  resistances  to  overcome;  but  the  firmness  of  this 
muscle  may  in  some  measure  arise  from  its  action,  which  1 called 
the  second  cause  of  firmness. 

Some  muscles  in  the  more  perfect  animals  are  much  firmer  than 
others  in  the  same  animal ; such  is  the  muscle  which  draws  the 
snail  into  its  shell,  and  retains  it  there  against  almost  any  power 
that  can  be  applied ; also  the  muscle  which  shuts  the  two  shells  of 
the  bivalve  is  very  firm  in  its  texture,  and  we  know  that  itis  exceed- 
ingly strong. 

A difference  is  sometimes  found  in  firmness  between  the  muscles 
of  the  male  and  female;  this,  however,  is  not  universal,  not  taking 
place  in  fish  ; but  in  all  animals  where  the  males  have  a disposition 
to  fight  and  the  females  not,  or  at  least  in  a less  degree,  I believe 
the  muscles  of  the  male  are  much  firmer  than  those  of  the  female, 
and  this  in  proportion  as  their  disposition  for  fighting  is  greater; 


280 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


therefore  in  beasts  of  prey,  where  the  disposition  to  fight  is  nearly 
equal  in  the  male  and  female,  the  difference  in  strength  is  not  so 
remarkable  as  in  many  other  animals,  there  being  very  little  ditfer- 
ence  between  a male  and  female  cat,  a dog  and  bitch,  a male 
and  female  hawk,  &c. ; but  the  muscles  appropriated  for  catching 
prey,  and  also  for  fighting,  are  much  firmer  than  the  other  muscles 
in  the  same  body  allotted  for  common  purposes,  and  according  to 
our  reasoning  they  must  be  much  stronger. 

We  find,  however,  in  animals  which  do  not  catch  prey,  and 
where  the  male  has  a strong  tendency  to  fight  with  the  males  of 
its  own  species,  while  the  female  has  this  disposition  very  little,  if 
at  all,  that  there  is. a very  considerable  difference  in  the  strength 
of  the  same  parts  in  the  male  and  female  while  alive,  and  a similar 
difference  in  the  firmness  of  their  muscles  after  death. 

There  is  a considerable  difference  between  the  muscles  of  a bull 
and  cow,  and  also  between  those  of  a cock  and  hen. 

Besides  the  general  strength  of  the  muscles  of  those  males  who 
fight,  as  they  have  parts  which  are  intended  for  this  purpose,  we 
find  that  the  muscles  of  those  parts  far  exceed  all  their  other  mus- 
cles in  firmness ; as  the  muscles  in  the  neck  of  the  bull,  and  the 
legs  of  the  cock,  far  exceed  in  firmness  all  the  other  muscles  in  the 
body,  and  exceed,  therefore,  in  a much  greater  degree  the  muscles 
of  the  female. 

We  njay  also  observe,  that  all  those  muscles  in  the  male  imme- 
diately employed  in  fighting,  although  not  intended  for  this  action 
alone,  having  other  actions  which  are  common  to  the  female,  be- 
sides being  firmer  than  those  of  the  female,  are  very  considerably 
increased  in  size;  thus  the  muscles  of  the  neck  of  the  bull,  and  of 
the  stone  horse,  those  of  the  legs  of  the  cock,  &c.,  are  much  thicker 
and  larger  than  in  the  female. 

The  second  cause  of  firmness  in  a muscle,  and  which  contributes 
to  its  strength,  is  action,  or  what  is  commonly  called  exercise,  and 
which  has  in  general  been  considered  as  the  principal  cause  of 
sti'ength,  size,  and  firmness. 

This  may  be  called  accidental,  as  it  is  not  confined  to  any  order 
of  animals,  or  any  one  set  of  muscles  ; it  may,  however,  be  observ- 
ed, that  the  muscles  employed  in  progressive  motion  and  the  pur- 
poses above-mentioned,  are  more  subject  to  this  accidental  cause 
of  firmness  than  any  other  in  the  body,  both  from  the  natur’al  ac- 
tions of  the  body,  and  also,  being  naturally  firm  and  strong,  from 
more  readily  being  employed  in  violent  actions. 

Thus  we  find  the  muscles  employed  in  progressive  motion  are 
much  firmer  than  any  other  muscles  in  the  same  animal,  both  from 
nature  and  action,  except  in  those  in  the  fighting  males  (who  do 
not  catch  their  food  by  violence),  which  are  employed  for  that  pur- 
pose, as  in  the  neck  of  the  bull. 

The  heart  of  all  animals  partakes  strongly  of  the  two  causes  of 
firmness,  and  is  perhaps  the  firmest  muscle  in  the  body.  This  firm- 
ness in  the  heart  is  very  early  in  life,  for  in  the  small  embryo  the 


CROONIAN  LECTURES  ON  MUSCULAR  MOTION. 


281 


heart  is  a pretty  firm  manageable  part,  while  every  other  muscular 
part  of  the  animal  is  as  tender  as  jelly. 

Constant  action  not  only  gives  firmness  to  muscles,  but  increase 
of  size. 

The  epicure  is  no  less  sensible  of  the  effects  of  these  causes  of 
firmness  than  the  physiologist,  and  therefore  prefers  the  inactive 
parts  ; and  the  leg  of  the  woodcock,  the  breast  of  the  partridge, 
pheasant,  turkey,  &c.,  are  held  in  high  estimation.  He  even  takes 
pains  to  diminish  the  effects  which  arise  from  exercise,  &c.,  by 
feeding  animals  in  such  a way  as  to  prevent  them  taking  place. — 
Upon  this  principle  house  lamb,  veal,  &c.,  are  made  tender.  How 
delicious  to  the  sensualist  must  the  flesh  of  the  sloth  be,  if  the  ac- 
count of  its  motion  being  far  exceeded  by  a snail  is  true ! 

From  the  above  account  it  must  appear  that  muscles,  in  propor- 
tion as  they  are  firm  in  texture,  will  be  strong  in  action ; it  is  at 
least  demonstrable  in  the  muscles  of  the  same  animal  whose  texture 
is  diflerent,  and  in  similar  muscles  in  the  male  and  female  of  the 
same  species,  and  we  may  reasonably  suppose  that  it  will  hold  good 
in  diftez’ent  species ; and  therefore,  when  we  find  the  muscles  very 
firm  in  any  one  species,  we  may  conclude  that  this  species  is  stronger 
than  any  other  species  in  which  the  muscles  are  tender  and  soft. 

This  firmness  in  a muscular  fibre  we  may  suppose  to  arise  from 
the  density  of  its  component  parts,  or  those  parts  being  closer  to- 
gether, the  uniting  medium  being  less  in  quantity ; this,  however,  it 
is  perhaps  impossible  to  determine  exactly. 

That  this  idea  may  be  better  understood,  I shall  suppose  that  a 
part  composed  of  dense  parts  (aggregated)  at  a given  distance,  will 
be  firmer  than  a part  composed  of  less  firm  parts  at  the  same  dis- 
tance ; and  it  is  plain  that  a part  composed  of  any  given  substance 
will  be  dense  in  proportion  as  the  parts  of  that  substance  are  near 
to  each  other. 

It  may  probably  be  similar  to  iron  and  steel ; in  the  iron  the 
parts  or  crystals  which  compose  the-jmass  are  large,  and  perhaps 
not  regular.  In  the  steel  they  are  small,  and  probably  more  regular 
in  their  figure,  by  which  means  they  can  adapt  themselves  better 
to  each  other,  and  still  more  so  if  tempered,  according  to  the  degree 
of  temper,  so  that  their  crystals  shall  become  still  smaller,  and  of 
course  the  whole  becomes  harder. 

To  ascertain  whether  the  firm  muscles  really  contained  more 
matter,  and  were  therefore  specifically  heavier  than  the  soft,  I made 
several  experiments  upon  muscles  of  different  densities.  The  ex- 
periments were  made  upon  the  same  muscle  of  Iw’o  animals  of  the 
same  species  whose  muscles  are  of  different  densities,  viz.,  the  mus- 
cles of  the  neck  of  the  ox  and  bull.* 

Nine  ounces  and  a half  of  muscle  from  a bull’s  neck,  and  the 

* My  reason  for  choosincr  those  muscles  in  preference  to  others  was,  that  they 
admit  a greater  degree  of  difference  in  firmness,  and  that  they  have  no  tendons 
intermixed,  so  as  to  give  density  from  that  cause. 

25* 


282 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


same  quantity  from  that  of  an  ox,  were  weighed  in  water,  when 
the  bull’s  was  thirty-one  grains  heavier,  which  is  about  -j|-g^th.^ 

From  this  experiment  it  appears  that  there  is  some  diflerence  in 
W'eight  between  a firm  muscle  and  one  that  is  naturally  soft  or  lax, 
although  not  great,  not  even  so  much  as  one  might  at  first  imagine, 
at  least  not  so  much  as  the  apparent  difference  in  density. 

As  it  appears,  from  the  above  observations,  that  with  the  same 
given  size  the  firmer  muscles  are  the  strongest,  it  becomes  a ques- 
tion why  every  muscle  in  the  bodies  of  the  more  perfect  animals, 
and  in  the  young  of  such  animals,  as  also  the  muscles  of  the  more 
simple  animals  in  general,  should  not  all  have  been  of  this  texture, 
which  constitutes  the  greatest  power  of  contraction  1 This  is  per- 
haps not  yet  to  be  fully  answered.  It  certainly  would  have  ren- 
dered many  parts  of  the  more  perfect  animals  much  smaller  than 
what  they  now  ai’e,  and  would  have  had  the  same  effect  upon  the 
whole  body  of  the  young  of  the  more  perfect  animals,  as  also  of 
the  more  simple  animals  universally;  we  must,  however,  suppose 
that  it  would  have  been  attended  with  some  inconveniences, 
although  at  present  what  these  inconveniences  would  have  been 
may  not  be  perfectly  understood. 


26.  THE  USE  OF  THE  OBLIQUE  MUSCLES. 

Muscles  are  the  active  parts  in  an  animal  body,  producing  dif- 
ferent effects,  according  to  the  circumstances  in  which  they  are 
placed;  and  the  greater  number  of  parts  requiring  a variety  of 
motions,  it  became  necessary  to  have  a variety  of  muscles  suited 
to  such  motions. 

The  function  of  a muscle  depends  on  the  contraction  of  its  fibres ; 
and  the  most  general  effect  produced  by  this  contraction  is  to  move 
some  one  part  of  the  body  upon  another.  But  we  may  observe, 
that  when  motion  in  a part  is  performed  by  one  set  of  muscles, 
there  are  other  muscles  employed  in  regulating  that  motion,  as  in 
most  joints;  and  in  a whole  part,  destined  to  a variety  of  motions, 
and  composed  of  smaller  parts,  intended  likewise  to  have  their  dis- 
tinct motions,  we  find  muscles  appropriated  for  lhe  purpose  of 
keeping  some  of  those  parts  fixed  in  a particular  position,  while  the 
whole  part  is  to  be  moved  by  other  muscles,  according  to  the 
nature  of  the  action  to  be  performed.  This  will,  perhaps,  be  best 
illustrated  by  attending  to  what  takes  place  in  the  eye,  considering 
it  as  part  of  the  head. 

The  eye  being  an  organ  of  sense,  which  is  to  receive  impressions 
from  without,  it  was  necessary  it  should  be  able  to  give  its  motions 


* [See  note,  p.  266.] 


THE  USE  OF  THE  OBLIQUE  MUSCLES. 


283 


that  kind  of  direction  as  would  permit  its  being  impressed  by  objects 
whether  at  rest  or  in  motion,  or  moving  from  object  to  object ; 
and  it  was  also  necessary  that  there  should  be  a power  capable  of 
keeping  the  eye  fixed  upon  an  object  when  our  body  or  head  was 
in  motion. 

For  the  better  understanding  this  action  of  pointing  the  eye 
towards  objects  under  the  various  circumstances  of  vision,  it  wdll 
be  necessary  to  mention  that  the  eye  is  furnished  with  muscles, 
some  of  which,  in  the  quadruped,  bird,  amphibia,  and  fishes,  are 
called  straight,  from  their  being  placed  in  the  direction  of  or  parallel 
to  the  axis  of  the  eye  ; and  two,  I believe,  have  always  been 
named  oblique.  Of  the  straight,  some  animals  have  more  than 
others.  There  are  four  straight  muscles  common  to  most  animals  ; 
and  those  which  have  more  have  the  additional  muscles  inserted 
immediately  in  the  eyeball  on  its  posterior  surface,  and  surround- 
ing the  optic  nerve.  The  four  straight  muscles,  which  are  common 
to  all  quadrupeds  pass  further  forwards,  and  are  rather  inserted 
towards  the  anterior  surface  of  the  eye. 

For  vision  at  large  it  was  not  only  necessary  that  the  eye  should 
be  capable  of  moving  from  object  to  object,  or  of  following  any 
object  in  motion,  but  also  necessary  that  there  should  be  a power 
to  keep  it  fixed  on  any  one  object  to  which  the  mind  might  be 
attentive  ; therefore  the  muscles  are  formed  so  as  not  only  to  be 
able  to  move  the  eye  from  object  to  object,  but  likewise  to  keep  its 
point  of  vision  fixed  upon  any  particular  one,  while  the  eye  is 
moving  progressively  with  the  head  or  body.  This  is  the  use  of  these 
muscles,  when  the  parts  from  whence  they  arise  are  kept  fixed 
respecting  the  objects  the  eye  is  pointed  to  ; but  it  is  often  neces- 
sary, while  the  eye  is  fixed  upon  a particular  object,  that  the  eye- 
ball and  the  head  in  which  it  is  fixed  should  shift  their  situation 
respecting  that  object ; and  this  would  alter  the  direction  of  the 
eye,  if  the  muscles  had  not  the  power  of  taking  up  an  action  that 
produces  a contrary  effect,  that  is,  keeping  the  point  of  insertion  of 
the  muscles  as  the  fixed  point,  by  causing  their  fibres  to  contract 
according  as  the  origins  of  the  muscles  vary  their  position  respect- 
ing the  object.  From  this  mechanism  we  find  these  three  modes 
of  action  produced  : first,  the  eye  moving  from  one  fixed  object  to 
another;  then  the  eye  moving  along  with  an  object  in  motion ; and,  last, 
the  eye  keeping  its  axis  to  an  object,  although  the  whole  eye,  and  the 
head,  of  which  it  makes  a part,  are  in  motion.  From  either  of 
these  motions  taking  place  singly,  or  being  combined,  the  eye  is 
always  kept  towards  its  object.  In  the  two  first  modes  of  action 
the  origins  of  the  muscles  are  fixed  points  respecting  the  object; 
and,  in  the  last,  the  object  becomes  as  it  were  the  centre  of  motion, 
or  fixed  point,  commanding  the  direction  of  the  actions  of  the  eye, 
as  the  north  commands  the  direction  of  the  needle,  let  the  box  in 
which  it  is  placed  be  moved  in  what  direction  it  may.  These  two 
first  modes  of  action  are  performed  by  the  straight  muscles  ; for 
the  head  being  a fixed  point,  they  are  capable  of  moving  the  eye 


284 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


up  and  down,  from  right  to  left,  with  all  the  intermediate  motions, 
which,  taken  together,  constitute  a circular  movement ; or,  when 
the  eye  is  to  become  the  fixed  point,  then  the  head  itself  performs 
the  circular  movement.  Thence  appears  the  necessity  why  the 
object,  the  axis  of  the  eye,  and  the  point  of  sensation,  should  all 
three  be  in  the  same  straight  line.  But  this  does  not  take  place  in 
all  movements  of  that  whole  of  which  the  eye  makes  a part;  for 
besides  those  which  we  have  already  taken  notice  of,  the  head  is 
capable  of  a motion  from  shoulder  to -shoulder,  the  axis  of  which  is 
through  the  axis  of  the  two  eyes,  from  the  fore  to  the  back  part. 
It  should  be  here  observed,  that  for  distinct  vision  the  object  must 
be  fixed  as  respecting  the  pupil  of  the  eye,  and  not  in  the  least 
allowed  to  move  over  its  surface.*  To  prevent  any  progressive 
motion  of  the  object  over  the  retina  of  the  eye,  either  from  the  mo- 
tion of  the  object  itself,  or  of  the  head  in  some  of  the  motions  of 
that  part,  the  straight  muscles  are  provided  as  has  been  explained  ; 
but  the  effects  wliich  would  arise  from  some  other  motion  of  the 
head,  as  from  shoulder  to  shoulder,  cannot  be  corrected  by  the 
action  of  the  straight  muscles,  therefore  the  oblique  muscles  are 
provided.  Thus  when  we  look  at  an  object,  and  at  the  same  time 
move  our  head  to  either  shoulder,  it  is  moving  in  the  arch  of  a 
circle  whose  centre  is  the  neck  ; and  of  course  the  eyes  would  have 
the  same  quantity  of  motion  on  this  axis  if  the  oblique  muscles  did 
not  fix  them  upon  the  object.  When  the  head  is  moved  towards 
the  right  shoulder  the  superior  oblique  muscle  of  the  right  side  acts 
and  keeps  the  right  eye  fixed  on  the  object;  and  a similar  effect  is 
produced  upon  the  left  eye  by  the  action  of  its  inferior  oblique  mus- 
cle: when  the  head  moves  in  a contrary  direction  the  other  oblique 
muscles  produce  the  same  effect.  This  motion  of  the  head  may, 
however,  be  to  a greater  extent  than  can  be  counteracted  by  tlie 
action  of  the  oblique  muscles.  Thus,  for  instance,  while  the  head 
is  on  the  left  shoulder  the  eyes  may  be  fixed  upon  an  object,  and 
continue  looking  at  it  while  the  head  is  moved  to  the  right  shoulder, 
which  sweep  of  the  head  produces  a greater  effect  upon  the  eye- 
balls than  can  be  counteracted  by  the  action  of  the  oblique  muscles ; 
and  in  this  case  we  find  that  the  oblique  muscles  let  go  the  eye, 
so  that  it  immediately  returns  into  its  natural  situation  in  the  orbit. 
Whether  this  is  performed  by  the  natural  elasticity  of  the  parts,  or 

* Optical  writers  seem  to  have  been  entirely  ignorant  of  this  ; for  they  not  only 
suppose  distinct  vision  compatible  with  the  object  liaving  a motion  over  the 
different  parts  of  the  retina,  buteven  explain  the  effects  which  would  be  produced 
by  it  on  the  mind  of  the  observer.  Iveill  makes  the  following  observation  : 

“ Since  optics  teach  us  that  every  body  which  is  visible  has  by  means  of  the 
rays  which  proceed  froin  that  object  its  image  painted  on  the  bottom  of  the  eye 
or  retina,  it  follows  that  those  objects  will  seem  to  be  moved  whose  images 
are  moved  on  the  retina,  that  is,  which  pass  over  successively  the  different  parts 
of  the  retina  whilst  the  eye  is  supposed  to  be  at  rest;  but  those  objects  will  be 
looked  upon  as  being  at  rest  whose  images  always  occupy  the  same  part  of  the 
retina,  that  is,  when  the  motion  of  those  images  are  not  perceived  in  the  bottom 
of  the  eye.” — Keill’s  Introduction  to  Natural  Philosophy,  p.  79. 


ON  THE  COLOUR  OF  THE  PIGMENTUM  OF  THE  EYE.  285 


whether  the  antagonist  oblique  muscles  take  up  the  action  and  rein- 
state the  eye,  I do  not  know.  If  the  head  still  continues  its  mo- 
tion in  the  same  direction,  then  the  same  oblique  muscles  begin  to 
act  anew,  and  go  on  acting,  so  as  to  keep  the  eyes  fixed  on  the 
object.  As  this  motion  of  the  head  seldom  takes  place  uncombined 
with  its  other  motions,  some  of  the  straight  and  oblique  muscles 
w'ill  be  employed  at  the  same  time,  according  as  the  motions  are 
miore  or  less  compounded. 


27.  ON  THE  COLOUR  OF  THE  PIGMENTUM  OF  THE 
EYE  IN  DIFFERENT  ANIMALS. 

Lv  the  eyes  of  all  animals  which  I have  examined  there  is  a sub- 
stance approaching  to  the  nature  and  appearance  of  a membrane, 
called  the  pigmentum,  which  lines  the  choroid  coat,  and  is  some- 
what similar  to  the  rete  mucosum  which  lies  under  the  cuticle  of 
the  human  body;  and  there  is  also  some  of  the  same  kind  of  sub- 
stance diffused  through  the  cellular  membrane  which  unites  the 
choroid  with  the  sclerotic  coat.  My  intention  at  present  is  only  to 
communicate  the  observations  I have  made  on  this  subject  and  its 
use,  confining  myself  to  the  consideration  of  that  kind  of  it  which 
lines  the  tunica  choroides  of  the  class  Mammalia,  and  of  birds;  in 
doing  which  I shall  also  take  occasion  to  speak  of  the  difference  of 
colour  occurring  in  animals  of  the  same  species.  Although  an  ac- 
curate examination  of  the  appearances  of  a similar  substance  in  the 
eyes  of  some  fishes  might  illustrate  the  subject,  we  cannot  avail  our- 
selves of  that,  as  from  not  being  sufficiently  acquainted  with  the 
effects  of  light  upon  the  eyes  of  that  class  of  animals. 

The  propagation  or  continuance  of  animals  in  their  distinct  classes 
is  an  established  law  of  Nature,  and  in  a general  way  is  preserved 
with  a tolerable  degree  of  uniformity  ; but  in  the  individuals  of  each 
species  varieties  are  every  day  produced  in  colour,  shape,  size,  and 
disposition.  Some  of  these  changes  are  perm.anent  with  respect  to 
the  propagation  of  the  animal,  becoming  so  far  a part  of  its  nature 
as  to  be  continued  in  its  offspring. 

Animals  living  in  a free  and  natural  state  are  subject  to  few 
deviations  from  their  specific  character  ; but  nature  is  less  uniform 
in  its  operations  when  influenced  by  culture.*  Considerable  varie- 
ties are  produced  under  such  circumstances,  of  which  the  most  fre- 

* From  the  variations  produced  by  culture  it  would  appear  that  the  animal  is 
so  susceptible  of  impression  as  to  vary  Nature’s  actions  ; and  this  is  even  carried 
into  propagation.  Whether  this  takes  place  at  the  very  first  union  of  the  principles 
of  the  two  parents,  so  as  to  derive  its  existence  from  both  ; or  whether  it  takes 
its  formation  from  the  mother,  after  the  first  formation  of  the  embryo,  are  perhaps 
not  easily  determined. 


286 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


quent  are  changes  in  the  colour.  These  changes  are  always,  I 
believe,  from  the  dark  to  the  lighter  tints,  and  the  alteration  very 
gradual  in  certain  species,  requiring  in  the  canary-bird  several  gene- 
rations; while  in  the  crow,  mouse,  &c.,  it  is  completed  in  one.  But 
this  change  is  not  always  to  white,  though  still  approaching  nearer 
to  it  in  the  young  than  in  the  parent,  being  sometimes  to  dun,  at 
others  to  spotted,  of  all  the  various  shades  between  the  two  extremes. 
This  alteration  in  colour  being  constantly  from  dark  to  lighter,  may 
we  not  reasonably  infer  that  in  all  animals  subject  to  such  variation 
the  darkest  of  the  species  should  be  reckoned  nearest  to  the  original; 
and  that  where  there  are  specimens  of  a particular  kind,  entirely 
black,  the  whole  have  been  originally  black?  Without  this  suppo- 
sition it  will  be  impossible,  on  the  principle  I have  stated,  to  account 
for  individuals  of  any  class  being  black.  Every  such  variety  may 
be  considered  as  arising  in  the  cultivated  state  of  animals;  but 
whether,  if  left  to  themselves,  tliey  would  in  time  resume  their  ori- 
ginal appearance,  I do  not  know.* 

The  colour  of  the  pigmentum  of  the  eye  always  corresponds,  I 
believe,  with  that  of  tiie  hair  and  skin,  especially  if  the  animal  be 
only  of  one  colour,  but  is  principally  determined  by  the  hair  ; and 
the  most  general  colour  is  a very  dark  brown,  approaching  to  black, 
from  whence  it  had  the  name,  nigrum  pigmentum.f  The  colour 
diflers  in  different  classes  of  animals,  often  in  the  same  class, 
and  even  in  the  same  species.  In  the  human  it  is  most  com- 
monly dark,  in  the  ferret  kind  always  light,  and  its  difference  of 
colour  in  the  same  species  is  evident  from  the  variety  observable  in 
the  eyes  of  different  people.  There  is  even  a difference  of  colour 
in  the  same  eye  in  many  classes  of  animals,  in  all  of  the  cat  and 
dog  kind,  and  perhaps  in  most  part  of  the  granivoi'ous.  In  some  it 
is  partly  black,  and  partly  of  the  appearance  of  polished  silver  ; and 
in  many  classes  the  variation  from  dark  is  of  two  colours  : for  in 
the  cow,  in  sheep,  deer,  horses,  and  I believe  in  all  animals  feeding 
on  grass,  there  are  in  the  same  eye  certain  portions  of  it  white,  and 
others  of  a fine  green  colour.  The  difference  in  colour  of  this  pig- 
mentum in  the  eyes  of  different  animals  of  the  same  species  is  very 
remarkable  : in  the  human  species  it  is  of  all  the  different  shades 
between  black  and  almost  white,  and  the  same  variety  is  seen  in 
rabbits,  mice,  crows,  blackbirds,  &c.,  but  in  these  it  is  of  one  colour 
onlj^  in  the  same  eye.  Every  species  is,  perhaps,  subject  to  such 
variations;  and  some  of  these  are  so  extraordinary  as  with  pro- 
priety to  be  denominated  monstrous.J 

* Tn  vegetables,  I believe,  it  invariably  holds  good  that,  however  improved  by 
culture,  if  neglected,  they  soon  degenerate  into  their  first  state. 

f As  the  colour  of  this  membrane  corresponds  with  the  colour  of  the  skin  and 
hair  of  the  person,  it  is  probable  that  the  people  among  whom  it  first  got  the  name 
were  dark. 

:f  Perhaps  the  word  monstrous  is  too  strong,  or  not  exactly  just.  It  certainly 
may  be  laid  down  as  one  of  the  principles  or  laws  of  Nature  to  deviate  under 
certain  circumstances.  It  may  also  be  observed,  that  it  is  neither  necessary,  nor 
does  it  follow  that  all  deviations  from  the  original  must  be  a falling  off;  it  appears 


ON  THE  COLOUR  OF  THE  PIGMENTUM  OF  THE  EYE.  287 


The  variation  in  the  colour  of  the  pigmentum  in  different  species 
of  animals  seems  to  depend  on  a fixed  law  of  Nature;  but  the 
varieties  which  are  met  with  in  the  same  species  are  much  less 
constant,  being  merely  different  shades  approaching  to  black  or 
white.  But  the  extraordinary  circumstance  is  its  being  sometimes 
unusually  lighter  or  darker  in  individuals  of  the  same  species;  and 
this  difference  not  seldom  starting  up  in  the  young  without  any 
hereditary  principle  to  account  for  it. 

The  human  species  is  a striking  example  of  the  colour  of  the 
pigmentum  corresponding  with  that  of  the  skin  and  hair  ; and  though 
the  skin  and  hair  of  one  person  differs  very  considerably  from  the  skin 
and  hair  of  another,  yet  it  is  not  in  so  great  a degree  as  in  many 
animals.  There  are  cattle  perfectly  white,  white  sheep,  white  dogs, 
white  cats  and  rabbits  ; but  there  are  few  of  the  human  species  that 
we  can  say  are  perfectly  white.  They  rather  pass  from  the  black 
into  the  brown,  red,  and  even  light  yellow  ; and  we  find  this  pigmen- 
tum, although  only  of  one  colour,  varying  through  all  the  diflerent 
corresponding  shades.  In  the  African  negro,  the  blackness  of 
whose  hair  and  skin  are  great  distinguishing  characteristics,  this 
pigmentum  is  also  very  black.  In  the  mulatto,  who  has  not  the 
skin  so  dark  as  the  iVfrican,  but  the  hair  nearly  as  black,  this  pig- 
mentum is  of  a shade  not  quite  so  deep  ; yet  still  it  does  not  approach 
so  near  to  the  middle  tint  as  the  skin,  rather  following  the  colour  of 
the  hair.  In  people  of  a swarthy  complexion,  as  Indians,  Turks, 
Tartars,  Moors,  &c.,  we  find  the  hair  always  of  a jet  black,  and  this 
substance  of  a much  darker  brown  than  in  those  that  are  fair.  In 
those  of  very  dark  complexions,  and  having  very  black  hair,  although 
descended  from  fair  parents,  the  same  thing  holds  good.  There  are 
few  species  of  animals,  or  even  individuals  of  a species,  whose  bodies 
are  only  of  one  colour.  Crows  and  some  others,  are  exceptions; 
but  the  greatest  number  are  of  two  or  more,  being  variously  spotted 
or  streaked  either  with  different  colours,  or  with  shades  of  the  same. 
Many  species  ai'e  constantly  lighter  in  some  parts  of  the  body  than 
in  others  ; and,  with  a few  exceptions,  animals  are  generally  lighter, 
as  to  colour,  on  the  lower,  or  what  may  be  called  the  foreparts, 
than  on  the  upper  or  backparts.  The  fair  man  or  woman  may 
strictly  be  considered  as  a spotted  or  variegated  animal.  In  many 
persons  the  hair  of  the  head,  eyebrows,  eyelashes,  beard,  and  hair 
on  the  pubes,  all  vary  in  colour.  The  hair  of  the  three  first  may  be 
called  foetal,  and  are  oflener  all  of  the  same  than  of  a different 
colour;  the  two  last  are  to  be  considered  as  adult  hair,  and  are 
commonly  alike  in  colour,  which  yet  frequently  varies  from  that  of 
the  foetus,  which  last  is  more  liable  to  change  its  colour  than  the 
other  ; and  the  change  is  generally  that  of  growingdarker,  especially 
on  the  head  and  the  eyelashes.^  This  diflerence  in  the  colour  of 

just  the  eontrarj',  therefore  we  may  suppose  that  Nature  is  improving-  her  works, 
or  at  least  has  established  the  principle  of  improvement  in  the  body  as  well  as 
in  the  mind. 

* The  hair  growing  gray  is  not  in  the  least  to  the  present  purpose. 


283 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  hair  on  different  parts  of  the  body  is  not  so  observable  in  those 
nations  who  are  dark  or  swarthy,  as  in  people  inhabiting  many  of 
the  northern  climates. 

In  animals  which  are  variegated  let  us  observe  the  colour  of  this 
pigmentum,  and  we  shall  find  it  regulated  by  some  general  principle, 
and  corresponding  with  the  colour  of  the  eyelashes.  The  magpie, 
for  instance,  is  nearly  one-third,  or  fourth  part  white  ; and  the  two 
colours,  if  blended,  would  make  the  compound  gray;  but  the  eye- 
lashes being  black  the  pigmentum  is  black  also.  We  sometimes 
meet  with  people  whose  skin  and  hair  are  very  white  and  yet  the 
iris  is  dark,  which  is  a sign  of  a dark  pigmentum  ; but  if  we  examine 
more  carefully  we  shall  also  find  that  the  eyelashes  are  dark, 
although  the  eyebrows  may  be  the  colour  of  the  common  hair. 

As  the  colour  of  the  iris  in  the  human  species  is  probably  a pre- 
sumptive, though  not  a certain  sign  of  the  colour  of  this  pigmentum, 
we  ma37beled  to  suppose  that  in  those  who  have  the  iris  in  one  eye 
different  from  that  of  the  other,  this  substance  will  likewise  differ ; 
but  this  I cannot  determine,  never  having  examined  the  e^^eSof  any 
person  with  such  a peculiarity.  It  is  not  an  uncommon  circum- 
stance in  some  species  of  animals,  the  Angola  cat  seldom  having 
the  colour  of  the  iris  the  same  in  both  eyes. 

In  people  remarkably  fair,  whether  they  are  of  a race  that  is 
naturally  so,  or  what  may  be  called  monstrous  in  respect  to  colour, 
as  white  AUthiopians,  still  we  find  this  pigmentum  following  the 
colour  of  the  skin  and  hair,  being  in  some  of  a light  brown,  and  in 
others  almost  white,  according  to  the  colour  of  the  hair  in  such 
people. 

All  foals  are  of  the  same  colour,  and  whatever  that  may  be,  as 
they  grow  older  it  generally  becomes  lighter,  therefore  the  pigmen- 
tum in  them  is  almost  always  of  the  same  colour,  and  does  not 
seem  to  change  with  the  hair.  This  change,  however,  is  only  in 
the  hair,  and  not  in  the  skin,  the  skin  of  a white  or  gray  horse 
being  as  dark  as  the  skin  of  a black  one  : yet  thhre  is  a cream- 
coloured  breed  which  has  the  skin  of  the  same  colour,  whose  foals 
are  also  of  a cream-colour ; and  by  inspecting  the  parts  not  covered 
with  hair,  such  as  the  mouth,  anus,  sheath,  &c.,  these,  and  the 
pigmentum  of  the  eyes  of  such  horses,  are  found  of  a cream-colour 
likewise. 

In  the  pigmentum  of  the  rabbit  kind  there  are  all  the  degrees  of 
dark  and  light,  corresponding  with  the  colour  of  the  hair ; yet  there 
seem  to  be  exceptions  to  this  rule  in  some  white  rabbits  with  black 
eyes,  and  therefore  with  black  pigmentum  ; but  in  all  such  there  is 
either  a circle  of  black  hair  surrounding  the  eye  or  the  eyelashes, 
and  the  skin  forming  the  edge  of  the  lid  is  also  black.  In  many 
white  cattle  this  is  also  observable;  and  in  that  breed  of  dogs  called 
Danes  some  have  the  hair  surrounding  one  eye  black,  while  the 
hair  surrounding  the  other  is  white;  and  the  iris  of  the  one  is  often 
lighter  than  that  of  the  other.  This  circumstance,  of  the  iris  of  one 
eye  being  lighter  in  colour  than  that  of  the  other,  is  a common  thing 


ON  THE  COLOUR  OF  THE  PIGMENTUM  OF  THE  EYE.  289 


in  the  human  species  ; and  sometimes  only  one  half  of  the  iris  is 
light,  without  any  difference  in  the  colour  of  the  eyelash  or  eye- 
brow. Whether  this  difference  in  the  colour  of  the  iris  of  the  two 
eyes  in  the  same  animal  is  owing  to  the  pigmentum  being  different 
in  colour,  I do  not  know,  although  I rather  suspect  it  is  something 
similar  to  the  white  iris  in  horses,  which  makes  them  what  is  called 
wall-eyed. 

The  variation  of  colour  appears  most  remarkable  when  a white 
starts  up,  either  where  the  whole  species  is  black,  as  in  the  crow 
or  blackbird,  or  where  only  a certain  part  of  the  species  is  black 
(but  permanently  so),  as  a white  child  borne  of  black  parents ; and 
a perfectly  white  child,  whose  hair  is  white,  and  who  has  the  pig- 
mentum also  white,  though  born  of  parents  who  are  fair,  should  as 
much  be  considered  as  a play  of  Nature  as  the  others.  All  these 
lusus  naturas,  such  as  the  white  negro,  the  pure  white  child  of  fair 
parents,  the  white  crow,  the  white  blackbird,  white  mice,  &c.,  have 
likewise  a white  pigmentum  corresponding  with  the  colour  of  the 
hair,  feathers,  and  skin. 

Besides  the  circumstance  of  animals  of  the  same  species  differing 
from  one  another  in  colour,  there  are  some  distinct  species  which 
are,  as  far  as  we  know,  always  of  a light  colour,  and  in  them,  too, 
this  pigmentum  is  white  : the  animal  I allude  to  is  the  ferret. 

When  the  pigmentum  is  of  more  than  one  colour  in  the  same  eye, 
the  lighter  portion  is  always  placed  at  the  bottom  of  the  eye,  in  the 
shape  of  a half-moon,  with  the  circular  arch  upward,  the  straight 
line  or  diameter  passing  almost  horizontally  across  the  lower  edge 
of  the  optic  nerve,  so  that  the  end  of  the  nerve  is  within  this  lighter 
coloured  part,  which  makes  a kind  of  semicircular  sweep  above 
it.  This  shape  is  peculiar  to  the  cat,  lion,  dog,  and  most  of  the 
carnivorous  tribe ; in  the  herbivorous  the  upper  edge  being  irre- 
gular ; in  the  seal,  however,  the  light  part  of  this  pigmentum  is 
equally  disposed  all  round  the  optic  nerve,  and  is,  on  the  whole, 
broader  than  it  is  commonly  found  in  quadrupeds.  How  far  this 
increase  of  surface  is  an  approach  towards  the  fish  kind,  in  which 
it  is  wholly  of  this  metallic  white,  I will  not  pretend  to  say,  but  it  is 
probable,  as  the  animal  is  to  see  in  the  water  as  well  as  in  the  air, 
that  it  may  be  formed  circular,  the  better  to  correspond  with  the 
form  of  the  eyelids,  which  open  equally  all  around,  which  seems 
to  accord  with  what  is  observable  in  fishes,  they  being  without 
eyelids. 

The  colour  of  the  pigmentum,  whether  white  or  green,  or  both, 
has  always  a bright  surface,  appearing  like  polished  metal,  which 
appearance  animal  substance  is  very  capable  of  taking  on,  as  we 
see  in  hair,  feathers,  silk,  &c. 

After  having  taken  notice  of  the  various  colours  of  this  pigmen- 
tum in  different  animals,  both  w'here  permanent  and  where  it  ap- 
pears to  be  a play  of  Nature,  let  us  next  examine  what  effect  it  has 
upon  vision  in  both  cases,  whether  these  effects  are  similar,  or  if 
one  case  illustrates  the  other. 


26 


290 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


It  may  be  asserted  as  an  undoubted  fact,-  that  the  light  which 
falls  on  the  retina  covering  a white  pigmentum  has  more  effect 
than  when  it  falls  on  the  retina  which  covers  a dark  one ; which 
is  known  by  comparing  the  vision  of  those  of  the  same  species  who 
have  the  pigmentum  wholly  dark  with  those  who  have  it  perfectly 
white  ; and  something  may  be  learned  by  a similar  comparison  of 
animals  who  have  it  only  in  different  species,  it  being  reasonable, 
from  analogy,  to  suppose  that  some  such  eflect  is  produced  in  the 
eye  which  is  possessed  of  both. 

I shall  first  consider  the  effect  produced  when  the  white  or  light 
colour  makes  only  part  of  the  pigmentum.  This  will  lead  me  to 
observe,  that  all  animals  having  the  pigmentum  diversified,  though 
they  are  capable  of  bearing  as  much  light  as  others,  and  can  see 
as  perfectly  when  light  is  in  an  equal  degree  ; can  likewise  see 
very  distinctly  when  the  light  is  much  less  than  will  serve  the 
purposes  of  animals  having  it  wholly  dark.  May  we  not,  therefore, 
ascribe  this  advantage  to  the  pigmentum  being  partly  white?  One 
might  be  almost  tempted  to  suppose  that  such  animals  have  a power 
of  presenting  the  different  parts  of  the  eye  to  the  light,  accord- 
ing to  the  quantity  of  light  required;  or  of  moving  the  crystalline 
humour  higher  or  lower  : but  we  are  at  present  unacquainted  with 
any  power  in  the  eye  by  which  these  actions  can  be  performed. 

We  may  observe,  that  when  a cat  or  dog  looks  at  us  in  the  twi- 
light the  whole  pupil  is  enlarged  and  illuminated,  but  in  a full  light 
there  is  no  such  appearance.  It  is  plain  there  must  be  a reflexion 
of  light  from  the  bottom  of  the  eye  to  produce  the  above  effect, 
especially  as  the  light  reflected  is  always  of  the  colour  of  the  pig- 
mentum  in  such  animals,  which  in  the  cow  is  of  a light  green. 

I shall  secondly  consider  those  animals  which  have  the  whole 
pigmentum  of  a white  colour,  whether  it  is  accidental  or  natural, 
and  that  see  much  better  in  the  dark,  or  with  less  light  than  those 
in  which  it  is  of  a dark  colour;  of  the  first  of  these  I shall  take  my 
instance  from  the  human  species;  of  the  second  the  ferret  will 
serve  as  an  example. 

Those  of  the  human  species  who  have  the  pigmentum  of  a light 
colour  see  much  better  with  a less  degree  of  light  than  those  who 
have  it  dark;  and  this  in  proportion  to  their  fairness ; for  when  the 
hair  is  quite  white  they  cannot  see  at  all  in  open  day  without  knit- 
ting their  eyebrows  and  keeping  the  eyelids  almost  shut.  In  many 
of  these  instances  there  is  an  universal  glare  of  light  from  the  pupil, 
tinged  with  a shade  of  red,  which  colour,  most  probably,  arises 
from  the  blood  in  the  vessels  of  the  choroid  coat.  I have  likewise 
observed  that  the  pigmentum  is  thinnest  when  it  is  light,  so  that 
some  of  the  light  which  is  reflected  from  the  point  of  vision  would 
seem  to  be  thrown  all  over  the  inner  surface  of  the  eye,  which  being 
white,  or  rather  a reddish-white,  the  light  appears  to  be  again  re- 
flected from  side  to  side,*  This  seemed  to  be  the  case  in  a boy  at 

* How  far  this  is  really  the  case  I do  not  absolutely  say  ; for  whatever  light 
comes  through  the  pupil  must  be  reflected  from  the  point  of  vision^;  but  I imagined 
I saw  the  light  passing  through  the  substance  of  the  iris. 


ON  THE  COLOUR  OF  THE  PIGMENTUM  OF  THE  EYE.  291 


Shepperton,  when  about  three  years  of  age,  of  whom  I have  a por- 
trait, to  show  that  appearance.  He  is  now  about  thirteen  years  of 
age:*  the  common  light  of  the  day  is  still  too  much  for  him  ; the 
twilight  is  less  offensive.  When  in  a room  he  turns  his  eyes  from 
the  window,  and  when  made  to  expose  his  face  to  the  light,  or 
when  out  in  the  open  air,  he  knits  his  eyebrows,  half  shuts  his  eye- 
lids, and  bends  his  head  forwards,  or  a little  down ; yet  the  light 
appears  to  be  less  obnoxious  to  him  now  than  formerly,  probably 
from  habit.  Such  persons  appear  to  be  nearer-sighted  than  people 
in  common,  but  I apprehend  that  appearance  to  arise  from  the 
position  into  which  they  throw  the  eyelids  and  eyebrows,  which  not 
only  in  a great  degree  excludes  the  light,  making  the  object  faint  in 
proportion  to  the  contraction  of  the  pupil  and  shade  made  by  the 
eyelids  and  eyebrows,  but  at  the  same  time  fits  the  eye  to  see 
near  objects;  for  if  we  nearlv  close  our  eyelids  and  knit  our  eye- 
brows we  can  see  a small  object  much  nearer  than  if  we  did  not 
perform  such  actions,  and  it  will  make  above  a foot  difference  in 
the  focal  distance  of  the  eye. 

In  many  rabbits  who  have  white  eyelashes,  and  in  white  mice, 
the  pigmentum  is  entirely  white,  which  is  likewise  observable  in  a 
certain  distinct  species  of  animals,  the  ferret,  which  we  have  ad- 
duced as  an  example  of  the  pigmentum  being  naturally  white;  for 
these  animals  being  intended  to  see  in  the  dark,  and  their  mode  of 
life  not  exposing  them  to  the  light,  they  are  liable  to  be  affected  by 
strong  light  to  a greater  degree  than  many  others. 

If  it  is  allowed  as  probable  that  in  animalshaving  the  pigmentum 
diversified  the  object  to  be  viewed  is  thrown  upon  the  lighter 
coloured  portion,  how  does  it  happen  that  such  are  able  to  bear  the 
light  better  than  those  who  have  the  pigmentum  altogether  of  a 
light  colour?  Perhaps  it  is  not  the  illuminated  object  itself  that  is 
ofiensive  to  the  retina,  but  that  diffusion  of  light  in  the  one  kind  of 
eye  which  does  not  happen  in  the  other. 

Having  stated  the  facts,  and  the  general  effect  arising  from  the 
diversified  pigmentum,  let  us  consider  the  manner  in  which  it  is 
brought  about,  that  such  animals  see  better  with  little  light  than 
those  which  have  the  pigmentum  wholly  black. 

Let  us  then  suppose  the  retina  to  be  the  organ  of  sight,  and  that 
by  the  rays  which  fall  upon  it  being  properly  refracted  it  gives  or 
conveys  to  the  mind  an  idea  of  a distinct  object,  corresponding  with 
the  sensation  of  touch.  This  is  the  most  common  and  simple  man- 
ner in  which  vision  is  performed,  and  is  that  mode  which  takes  place 
where  the  pigmentum  is  black,  or  nearly  so,  and  where  the  greatest 
quantity  of  external  light  is  required. 

The  retina,  although  somewhat  opaque,  is  yet  so  transparent  as 
to  allow  a considerable  quantity  of  light  to  pass  through  it.  For  if 
this  was  not  the  case  there  could  not  be  those  differences  in  the 
appearance  of  the  eye  which  I have  been  describing.  The  rays 
which  pass  through,  we  may  suppose,  do  or  do  not  give  sensation 

* The  period  here  alluded  to  is  1786,  when  the  first  edition  of  this  work  was 
published. 


292 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


ill  their  passage ; and  we  may  also  suppose  that  only  those  which 
strike  against  the  retina  are  the  cause  of  sensation:  but  this  is  not 
the  present  inquiry  ; the  rays  which  pass  through  the  retina  are 
what  I am  alone  to  consider,  which  falling  upon  the  pigmentum  are 
there  disposed  of  according  to  the  reflecting  powers  of  that  sub- 
stance. If  the  pigmentum  is  black  the  rays  will  then  be  absorbed, 
and  entirely  lost,  therefore  in  such  eyes  vision  can  receive  no 
assistance  from  it,  and  consequently  a considerable  quantity  of  light 
is  required  to  produce  distinct  vision  ; but  in  those  who  have  some 
part  of  this  pigmentum  white,  we  find  that  the  rays  of  light  which 
pass  through  the  retina  are  reflected  back  again  ; and  in  this  case  it 
is  not  unnatural  to  suppose  that  the  reflected  rays,  in  their  passage 
back,  will  strike  against  the  retina,  and  increase  the  power  of  vision. 
It  is  evident  that  a considerable  portion  passes  forwards  through  the 
retina,  which,  I suspect,  is  partly  lost  on  the  inner  surface  of  the 
lateral  and  forepart  of  the  eye,  where  the  pigmentum  is  black,  while 
the  remainder  passing  through  the  pupil  is  again  thrown  on  the 
object  looked  at.  The  next  thing  to  be  considered  is,  whether  the 
shape  of  the  eye  is  such  as  will  throw  the  rays,  which  passed  through 
the  retina,  back  upon  that  membrane,  in  the  same  or  nearly  in  the 
same  place  as  that  through  which  they  originally  came.  The  eye 
being  a sphere,  or  approaching  to  that  figure,  makes  it  probable; 
but  whether  the  curve  is  such  as  will  reflect  the  rays  exactly  in  the 
same  direction  is  not  so  easily  determined.  If  the  curve  be  a true 
one,  then  the  rays  that  are  not  obstructed  in  tlieir  return  by  the 
retina  must  pass  forwards  through  the  pupil,  and,  being  refracted  in 
their  passage  through  the  crystalline  humour,  will  be  sent  out  of  the 
eye  in  the  same  lines  in  which  they  entered,  and  be  thrown  on  the 
very  object  from  whence  they  came;  which  seems  to  be  in  a great 
measure  the  case,  if  M'e  may  judge  by  the  degree  of  illumination 
in  the  cat’s  eyes.  If  the  rays  reflected  from  the  light  part  of  the 
pigmentum  should  not,  in  their  return,  strike  exactly  on  the  same 
points  in  the  retina,  through  which  they  first  passed,  yet  if  they 
are  thrown  nearly  on  the  same  place  it  will  be  sufficient,  for  we 
know  that  our  sensations  are  not  capable  of  conveying  to  the  mind 
mathematical  exactness.  And  the  same  circumstance  will  be  a 
sufficient  answer,  should  it  be  objected  that  the  time  lost  in  the 
passing  and  repassing  of  the  rays  may  prevent  distinct  vision  ; for 
it  is  known  that  if  an  illumined  body  is  made  to  move  quickly  in  a 
circle,  it  will  appear  to  the  eye  a circle  of  fire. 


28.  SOME  PACTS  RELATIVE  TO  THE  LATE  MR.  JOHN 
HUNTER’S  PREPARATION  FOR  THE  CROONIAN 
LECTURE. 

BY  EVERARD  HOME,  ESQ.,  F.  R.  S. 

[Read  November  ]4, 1793.] 

Mr.  Hunter  having  announced  to  the  Royal  Society  that  he 
would  make  the  structure  of  the  crystalline  humour  of  the  eye  the 


PREPARATION  FOR  THE  CROONIAN  LECTURE. 


293 


subject  of  the  Croonian  lecture  for  the  present  year,  and  having,  un- 
fortunately for  science,  died  before  his  observations  on  that  subject 
were  rendered  complete,  I feel  it  a duty  I owe  to  his  memory  as 
well  as  to  the  Society,  to  state  the  facts  respecting  this  humour 
with  which  he  had  acquainted  me  ; and  shall  subjoin  an  unfinished 
letter  from  Mr.  Hunter  to  Sir  Joseph  Banks  on  the  same  subject. 

It  is  now  many  years  that  Mr.  Hunter  has  had  an  idea  that  the 
crystalline  humour  was  enabled  by  its  own  internal  actions  to  adjust 
itself,  so  as  to  adapt  the  eye  to  different  distances ; and  w’hen  the 
TcEnia  hydatigena*  first  came  under  his  observation  as  a living  ani- 
mal, he  was  surprised  to  see  the  quantity  of  contraction  that  took 
place  in  a membrane  devoid  of  muscular  fibres,  but  made  use  of 
the  facts  in  his  investigation  of  the  structure  of  the  crystalline  hu- 
mour of  the  eye. 

Some  time  after  this,  having  occasion  to  dissect  the  eye  of  the 
cuttle-fish,  which  he  had  frequently  done  before,  but  not  with  exact- 
ly the  same  view,  he  discovered  in  the  crystalline  humour  a struc- 
ture which  corresponded  with  the  idea  he  had  formed  of  its  actions 
in  the  human  eye.  He  found  it  composed  of  laminae,  whose  ap- 
pearance was  evidently  fibrous  for  some  depth  from  the  external 
surface  ; but  becoming  less  and  less  distinct,  till  at  last  this  fibrous 
appearance  was  entirely  lost,  and  the  middle,  or  central  part  of  the 
humour,  was  compact  and  transparent,  without  any  visible  laminae. 
From  this  structure  it  would  appear  that  in  the  eye  of  the  cuttle-fish 
the  exterior  parts  of  the  humour  are  fibrous,  the  interior  parts  not} 
so  that  the  central  parts  is  a nucleus  round  which  the  fibrous  cover- 
ings are  placed.  The  preparations  which  demonstrate  these  facts 
will  be  laid  before  the  Society. f 

As  the  structure  of  the  crystalline  humour  in  the  cuttle-fish  dif- 
fers in  nothing  from  that  of  the  same  humour  in  other  animals  but 
in  the  distinctness  of  the  fibrous  appearance,  Mr.  Hunter  was  led 
to  consider  that  the  exterior  part  in  all  of  them  was  similar,  although 
no  appearance  of  fibres  could  be  demonstrated. 

What  I have  here  explained  I was  acquainted  with  at  the  time  I 
had  the  honour  of  giving  the  Croonian  lecture,  in  which  I ex- 
amined the  different  structures  endowed  with  muscular  action,  and 
was  desirous  that  Mr.  Hunter  would,  either  of  himself  or  through 
me,  communicate  these  observations  to  the  Society;  but  this  he 
declined  doing  till  he  had  ascertained  by  experiment  whether  any 
muscular  effect  was  really  produced  ; and  the  hope  of  being 
assisted  by  Mr.  Rarnsden  made  him,  from  time  to  time,  put  off 
making  his  experiments. 

In  the  course  of  this  season  he  began  his  experiments,  which 
were  founded  upon  the  analogy  that  ought  to  exist  between  this 

* [The  hydatid  commonly  found  in  the  abdominal  cavity  of  the  sheep, — Cysli- 
cercus  tenuicnilis,  Rudolphi.] 

f [The  Hunterian  preparations  demonstrating  the  peculiarities  of  the  eye 
of  the  cuttle-fish  are  not  fewer  than  twenty.  See  Physiological  Catalogue, 
vol.  iii.,  p.  140.] 


294 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


humour,  if  muscular,  and  others  of  a similar  structure,  which  led 
him  to  expect  that  they  would  be  acted  upon  by  the  same  stimuli; 
and  having  found  that  a certain  degree  of  heat,  applied  through 
the  medium  of  water,  will  excite  muscular  action  after  almost 
every  other  stimulus  had  failed,  it  was  proposed  to  apply  this  to  the 
crystalline  humour,  and  ascertain  its  effects. 

The  crystalline  humour  taken  from  animals  I'ecently  killed  must 
be  considered  as  being  still  alive.  Such  humours  were  to  be  im- 
mersed in  water  of  different  temperatures,  and  placed  in  such  a 
manner  as  to  form  the  imago  of  a lucid,  well-defined  object,  by  a 
proper  apparatus  for  that  purpose,  so  that  any  change  of  the  place 
of  that  image  from  the  stimulating  effects  of  the  warm  water  upon 
the  humour  would  be  readily  ascertained.  These  were  the  experi- 
ments which  Mr.  Hunter  had  instituted  and  begun;  but  in  which 
he  had  not  made  sufficient  progress  to  enable  him  to  draw  any  con- 
clusions. 

To  Sir  Joseph  Banks,  froin  Mr.  Hunter. 

“ Sir, 

“ When  I did  myself  the  honour  of  giving  in  my  claim  to  the  dis- 
covery of  the  crystalline  humour  being  muscular,  and  proposed  to 
make  it  the  subject  of  the  Croonian  lecture,  I did  not  foresee  that 
anything  could  prevent  me  from  fulfilling  my  promise;  but  since 
that  time,  what  with  my  state  of  health,  which  does  not  allow  me 
to  be  very  active,  the  hurry  of  otlicial  business  on  account  of  the 
war,  and  my  brother-in-law,  Mr.  Home,  being  employed  on  the 
medical  staff,  I have  not  had  the  power  of  repeating  my  experi- 
ments, and  drawing  out,  to  my  satisfaction,  the  many  conclusions 
which  are  the  result  of  such  a power  in  this  humour. 

“ The  laws  of  optics  are  so  well  understood,  and  the  knowledge 
of  the  eye,  when  considered  as  an  optical  instrument,  has  been 
rendered  so  perfect,  that  I do  not  consider  myself  capable  of  making 
any  addition  to  it : but  still  there  is  a power  in  the  eye  by  which  it 
can  adapt  itself  to  difierent  distances  far  too  extensive  for  the  simple 
mechanism  of  the  parts  to  efiect.  This  power  writers  upon  this 
subject  have  been  at  great  pains  to  investigate  and  explain.  The 
motion  of  the  crystalline  humour  forwards  and  backwards  was 
asserted  by  some  to  be  the  cause,  while  others  supposed  in  the  eye 
a power  to  alter  its  shape,  so  as  to  shorten  or  lengthen  its  axis, 
which  altered  the  distance  between  the  crystalline  humour  and  the 
point  of  impression  ; but  we  should  consider  that  a part  of  the  e}'e 
is  itself  a refractor,  and  that  if  its  shape  be  altered  so  as  to  remove 
the  crystalline  humour  from  the  point  of  impression,  in  order  to 
enable  it  to  bring  a distant  object  to  its  proper  focus  on  the  retina, 
this  effect  will  be  in  some  degree  counteracted  by  the  anterior  part 
of  the  eye  refracting  more  than  before,  by  being  rendered  more 
convex.  But  we  have,  in  fact,  no  power  capable  of  producing  this 
effect : for  the  straight  muscles,  so  far  from  appearing  to  have  this 


PREPARATION  FOR  THE  CROONIAN  LECTURE. 


295 


power,  have  been  even  supposed  to  flatten  the  eye,  and  shorten  its  axis  ; 
and  it  is  very  possible  that  the  action  of  these  muscles  is  such  as 
tends  to  both  effects ; but,  being  in  opposition  to  each  other,  the 
eye  retains  its  shape,  the  insertion  of  these  muscles  being  much  more 
forwards  than  appears  to  be  necessary  for  the  simple  motions  of 
the  eye.  Further,  when  we  consider  that  in  many  animals  the 
shape  of  the  eye  is  unalterable,  as  in  all  of  the  whale  tribe,  the 
sclerotic  coat  being  above  half  an  inch  thick  and  composed  of  a 
strong  tendinous  substance  ; — that  in  many  fish  this  coat  is  com- 
posed of  cartilage ; and  in  all  birds  the  anterior  part  of  it  is  (I  be- 
lieve) composed  of  bone ; — from  all  these  considerations,  I saw  no 
power  that  could  adapt  the  eye  to  the  various  distances  of  which 
we  find  it  capable  in  the  human  body,  unless  we  suppose  the  crys- 
talline humour  to  be  varied  in  figure,  which  can  only  be  effected 
by  a muscular  action  within  itself.  With  this  idea  strongly  im- 
pressed upon  my  mind,  and  finding  that  in  many  animals,  when  the 
crystalline  humour  was  coagulated,  it  had  a fibrous  structure  like 
muscles,  I confess  it  seemed  to  me  to  confirm  it ; but  as  this  might 
to  others  appear  only  conjecture,  requiring  some  proof,  I set  about 
such  experiments  as  were  best  adapted  for  that  purpose.  Knowing 
that  in  all  violent  deaths  the  muscles  contract,  I supposed  the  crys- 
talline humour,  if  muscular,  would  show  signs  of  this  effect ; for 
which  purpose  I got  the  eyes  of  bullocks  when  removed  from  the 
sockets,  the  moment  the  animal  was  knocked  down,  and  while  he 
eyes  were  warm  the  humours  were  removed.” 

Mr.  Hunter  had  proceeded  thus  far  in  the  account  of  his  experi- 
ments, when  he  was  suddenly,  and  very  unexpectedly,  carried  off; 
and  as  he  has  left  no  notes  upon  this  subject,  I am  unable  to  make 
any  addition  to  the  account  I have  already  given. 

Mr.  Hunter’s  laying  claim  to  the  discovery  of  a fibrous  structure 
in  the  crystalline  humour,  which  had  been  observed  long  before, 
and  described  by  the  accurate  Leuwenhoek,  may  appear  to  require 
some  explanation.  The  discovery  of  a fibrous  appearance  in  that 
humour  appertains  to  Leuwenhoek;  but  the  discovery  of  an  eye 
in  which  this  structure  of  the  crystalline  humour  was  perfectly  dis- 
tinct, and  in  which  all  the  circumstances  of  course  and  situation 
could  be  determined,  is  due  to  Mr.  Hunter:*  and  if  it  should  be 

* [In  this  investigation  by  Hunter  of  the  intimate  structure  of  the  crystalline 
lens  vve  may  perceive  the  continuation  of  the  series  of  discoveries  which,  com- 
menced by  Leuwenhoek,  have,  in  the  hands  of  Sir  David  Brewster,  jiroduced 
such  unexpected  results,  and  opened  so  interesting  a field  for  philosophical  ex- 
periment and  teleological  speculation  with  regard  to  this  part  of  the  mechanisna 
of  the  instrument  of  vision. 

Notwithstanding  the  anatomical  remarks  of  Hunter,  the  observation  of  Professor 
Blair  (^Edinburgh  transactions,  vol.  iii.),  and  the  experiments  of  Young,  Wol- 
laston, Wells,  and  Frauenhofer,  we  still  find,  even  in  very  recent  physiological 
works,  a mere  repetition  of  the  simple  statement  of  Paley  that  the  lens  consists 
of  concentric  layers,  which  gradually  increase  in  density  from  the  circumference 
to  the  centre;  and,  under  the  influence  of  an  apt  comparison,  the  principle  of  the 
construction  of  the  lens  is  asserted  to  be  the  same  as  that  of  the  compound  or 
achromatic  object-glass,  and  the  invention  of  Dollond  to  be  a repetition,  though 


296 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


lound,  by  future  observation  and  experiments,  that  this  structure, 
which  is  different  from  any  that  has  hitherto  been  described,  is  ca- 

an  imperfect  one,  of  this  the  natural  type  and  perfection  of  a dioptric  instrument 
which  is  supposed  to  converge  the  rays  of  light  into  a focus  without  any  dispersion 
of  the  rays,  and  consequently  without  the  production  of  false  colours  round  the 
image.  Now  the  fact  is  that  the  image  given  by  the  eye  is  not  perfect  with 
regard  to  colours  in  its  ordinary  exercise  : there  is  not  only  dispersion  of  the  rays 
of  light,  but  the  quantity  of  dispersion  has  been  measured,  and  the  different  focal 
lengths  of  the  eye  for  red  and  violet  lights  have  been  accurately  determined  by 
Young  and  Fraueiihofer ; the  latter  philosopher,  indeed,  has  found  it  necessary 
to  correct  the  dispersion  of  the  eye  in  the  construction  of  his  achromatic  object- 
glasses.  But  to  return  to  the  structure  of  the  crystalline  lens, — this  complex  and 
beautiful  part  consists,  according  to  Sir  David  Brewster,  of  innumerable  fibres 
of  nearly  the  same  length,  each  of  which  tapers  from  its  middle  part  to  its  two 
extremities,  like  the  gores  or  gussets  of  a globe.  In  the  lenses  of  some  animals 
the  extremities  of  all  the  fibres  terminate  in  two  opposite  poles  ; in  others,  in  a 
line  at  each  pole,  the  line  at  the  posterior  pole  being  at  right  angles  to  the  line 
at  the  anterior  pole,  and  all  the  fibres  except  a few  being  bent  into  the  most 
beautiful  curves  of  contrary  flexure.  In  some  lenses  the  fibres  terminate  in  the 
lines  of  a rectangular  cross  at  each  pole,  the  line  of  the  cross  at  one  pole  being 
inclined  45°  to  the  lines  at  the  other  pole  ; in  others,  the  terminations  of  the  fibres 
form  more  complicated  figures.  In  the  largest  number  of  animals  the  arrange- 
ment of  the  fibres  is  the  same  at  both  poles  ; but  in  a few,  such  as  the  turtle,  the 
fibres  terminate  in  a different  manner  in  the  two  surfaces  of  the  lens.  But  the 
structure  of  each  of  the  fibres  is  still  more  wonderful  than  their  arrangement.  The 
sides  of  each  fibre  are  formed  with  teeth,  like  those  of  a watch-wheel,  and  the 
teeth  of  one  fibre  lock  into  those  of  the  adjacent  ones,  apparently  to  strengthen 
them  and  give  body  to  the  frail  morsel  of  transparent  jelly  into  which  they  are 
so  marvellously  moulded. 

In  the  lens  of  a cod-fish,  four-tenths  of  an  inch  in  diameter.  Sir  D.  Brewster 
calculates  the  number  of  fibres  to  be  about  five  millions,  and  the  number  of  teeth  by 
which  the  fibres  are  bound  together  to  be  sixty-two  thousand  five  hundred  millions  ; 
and  as  every  tooth  has  three  surfaces,  the  number  of  touching  surfaces  will  be 
one  hundred  and  eighty-seve?!  thousand  five  hundred  millions ; and  yet  this  little 
sphere  of  tender  jelly  is  as  transparent  as  a drop  of  the  purest  water,  and  allows 
a beam  of  light  to  pass  across  these  almost  innumerable  joints  without  obstruct- 
ing or  reflecting  a single  ray  ! 

With  respect  to  the  muscular  theory  of  the  lens,  and  its  supposed  power  of 
adjusting  the  eye  to  vision  at  different  distances,  by  an  alteration  of  its  own 
form  or  dimensions,  it  is  hardly  necessary  to  state  that  these  views  have  derived 
no  support  since  the  time  of  Hunter,  and  of  Dr.  Young,  who  also  entertained  the 
theory  of  the  irritability  of  the  crystalline  fibres.  It  has,  on  the  other  hand,  been 
shown,  in  the  well-attested  case  of  Henry  Miles,a  that  the  eye  may  retain  its 
power  of  adjustment  after  the  removal  of  the  lens. 

The  supposed  function  of  the  lens,  as  an  achromatic  instrument,  has  been  de- 
duced from  the  structure  which  it  presents  in  the  human  body,  where  the  density 
of  the  fibrous  layers  diminishes  from  the  centre  to  the  surface  : a structure  of 
which  the  purpose  is  undoubtedly  to  correct  spherical  aberration:  but  the  lenses 
of  quadrupeds  display  three  difl'erent  structures  of  varying  density,  separated  by 
neutral  lines,  in  w'hich  lines  a density  decreasing  outw'ards  passes  into  a density 
increasing  outwards.  This  structure  is  well  displayed  in  the  lens  of  the  horse  ; 
and  when  the  animal  has  attained  a great  age  the  densities  of  the  central  and 
superficial  structures  have  become  uniform  throughout,  wdiile  the  middle  one 
exhibits  a varying  density  more  strongly  marked  than  in  the  young  lens,  and 
exhibiting  by  polarized  light  a brilliant  yellow  colour,  like  the  most  perfect  films 
of  regularly  crystallized  bodies.  That  these  structures  are  intended  to  correct 


a See  the  Croonian  Lecture,  Phil.  Trans.,  1802,  vol,  xcii.,  p,  8. 


OF  THE  ORGAN  OF  HEARING  IN  FISHES. 


297 


pable  of  producing  consequent  actions  and  effects,  sufficient  to  ex- 
plain the  adjustment  of  the  eye  to  different  distances,  it  will  not  be 
considered  as  a small  or  unimportant  discovery. 

The  melancholy  event  which  has  deprived  this  learned  Society 
of  so  valuable  a member,  and  which  has  taken  from  me  so  able  an 
instructor,  so  rare  an  example,  and  so  inestimable  a friend,  is  too 
recent  to  make  any  apology  necessary  for  the  shortness  or  incor- 
rectness of  this  account.  I thought  it  due  to  the  memory  of  my 
friend  that  no  promise  of  his,  however  inadequate  I feel  myself  to 
performance,  should  be  left  unfulfilled  ; and  the  circumstances  of 
distress  under  which  it  has  been  drawn  up  will  procure  for  me  every 
indulgence  from  this  learned  Society. 

Everakd  Home. 

Leicester  Square,  Nov.  4,  1793. 


29.  AN  ACCOUNT  OF  THE  ORGAN  OF  HEARING  IN 

FISHES.* 

Natural  history,  having  ever  been  considered  as  worthy  the 
attention  of  the  curious  philosopher,  has  in  all  ages  kept  pace  with 
the  other  branches  of  knowledge  ; and  as  both  arts  and  sciences 
have  of  late  years  been  cultivated  to  a degree  perhaps  beyond 

spherical  aberration  or  to  improve  vision  cannot  be  doubted  ; but  the  principles 
are  yet  to  be  discovered  on  which  that  correction  or  improvement  depends. 
Meanwhile  it  is  the  duty  of  the  physiologist  to  set  plainly  before  himself,  and  to 
offer  fairly  to  his  pupils  these  unexplained  or  residual  phenomena  of  the  theory 
of  vision  ; not  to  hide  them  beneath  an  easily  comprehended  but  insufficient 
illustration.  An  achromatic  lens,  though  highly  desirable,  indeed  essential  to 
the  construction  of  a good  telescope  or  microscope,  is  not  therefore  necessary  in 
the  eye  : it  is  well  known  to  be  less  adapted  for  the  purposes  of  a camera  obscura 
than  a common  lens;  but  the  organ  of  vision  has  a much  closer  analogy  to  a 
camera  obscura  than  to  a telescope.  In  a telescope,  if  there  be  colour,  or  disper- 
sion of  the  object-glass,  this  must  be  greatly  magnified  by  the  eye-piece;  and, 
what  is  still  more  essential,  there  is  an  eye  behind  the  instrument  which  takes 
cognizance  of  those  imperfections,  and  for  whose  sake  they  are  endeavoured  to 
be  remedied.  But  there  is  no  eye  behind  the  retina  to  view  in  the  same  manner 
the  image  which  is  thrown  upon  that  membrane.  It  is  well-known  that  the 
retina  is  incapable  of  transmitting  a distinct  idea  of  any  spectrum  depicted  upon 
it  save  of  that  which  is  situated  in  or  near  its  axis;  the  colours  of  the  lateral 
pencils  cannot  be  seen,  and  hence  it  is  of  no  importance  whatever  to  render  the 
image  achromatic  at  a distance  from  the  axis.  When  we  wish  to  examine  an  ob- 
ject, or  a part  of  an  object,  with  minute  attention,  we  direct  to  it  the  axis  of  the  eye  ; 
and  in  order  to  obtain  a sensible  colourless  vision  in  or  near  the  axis  achromatic 
compensation  is  not  necessary.  It  is  no  doubt  true  that  even  in  this  axis  there 
is  a non-coincidence  of  the  foci  of  the  differently-coloured  rays  ; but  owing  to  the 
shortness  of  the  focal  distance  of  the  eye,  and  the  low  dispersive  power  of  the 
humours,  this  non-coincidence  of  the  different  foci  does  no  injury  to  our  ordinary 
vision.] 

* [Originally  communicated  to  the  Royal  Society,  and  printed  in  the  Philoso- 
phical Transactions  (vol,  Ixxii.,  p.  379)  for  the  year  1782.] 


298 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


what  was  ever  known  before,  we  find  that  natural  history  has  not 
been  neglected.  All  the  nations  of  Europe  appear  solicitous  to 
encourage  the  study;  and  in  this  island  it  has  been  pursued  with 
more  philosophic  ardour  than  was  ever  known  in  any  country.  It 
has  become  an  object  of  pursuit  to  men  possessed  of  affluent  for- 
tune ; which  they  have  not  only  dedicated  to  the  cultivation  of  this 
science,  but  have  even  risked  their  health  and  lives  in  exploring 
unknown  regions  to  increase  the  sources  of  information,  and  in 
settling  correspondences  everywhere,  so  as  to  bring  materials  into 
this  country  that  might  render  it  the  school  of  natural  history.  It 
is  no  wonder  then  that  a spirit  of  inquiry  is  diffused  through  almost 
all  ranks  of  men;  and  that  those  who  cannot  pursue  it  themselves, 
yet  choosing  at  least  to  benefit  by  the  industry  of  others,  are  eager 
to  be  informed  of  what  is  already  known. 

These  reflections  have  induced  me  to  publish  this  short  account 
of  the  organ  of  hearing  in  fishes;  for,  although  the  existence  of 
such  an  organ  is  now  known  to  many,  it  is  still  a subject  of  dispute 
with  others  whether  they  possess  the  sense  or  not.* 

Some  time  before  I quitted  my  anatomical  pursuits,  in  the  year 
17G0,f  and  went  with  the  army  to  Belleisle,  I had  discovered  this 

* [Cuvier  justly  states  tliat  the  structure  of  the  organ  of  hearing  was  better 
known  to  some  of  the  ancient  anatomists  in  the  class  of  fishes  than  even  in  the 
human  subject.  Casserius  has  given  moderately  good  figures  of  the  semi-circu- 
lar canals  and  the  ossiculum  auditus  of  the  pike  in  his  work  entitled  Pentestesion 
(p.224),  published  in  the  year  1600.  Steno,  in  the  Acta  Medica  of  Copenhagen 
for  1673,  described  the  internal  ear  or  the  Squaliis  Mustelus,  Linn.,  with  tolera- 
ble exactness,  although  without  figures. 

Klein,  in  his  Missus  Hisiorise  Fiscium  permovenda;,  printed  in  the  }'ear  1740, 
gives  a detailed  description  and  accurate  figures  of  the  ossfcula  of  the  ear  of  the 
pike,  salmon,  trout,  umber,  marene  (^Sabno  Marxna,  L.),  herring,  cod,  dorsch 
(^Gadus  callarius,  L.),  ling,  pike-perch,  perch,  gremille,  stickleback,  turbot,  sole, 
barbue  {Pkuronectes  Rhombus,  L.),  carp,  barbel,  and  many  other  species  of 
Cyprinus. 

In  1753,  Etienne-Lonis  Geoffrey,  a physician  of  Paris,  presented  to  the 
Academy  a memoir  ex  prufesso  on  the  organ  of  hearing  in  fishes;  but  this  was 
not  printed  till  the  year  1778.  He  has  described  generally  the  ear  of  the  eel,  the 
cod,  the  pike,  the  carp,  the  gardon,  {Cyprinus  idus.  Bio.),  the  flounder,  and  the 
perch  ; but  he  errs  in  ascribing  to  certain  holes  in  the  cranium  the  office  of  a 
meatus  auditorius  externus,  which  they  do  not  fulfil.  The  figures  annexed  to 
this  memoir,  Cuvier  informs  us,  were  mislaid  and  lost,  and  therefore  they  did  not 
appear  in  the  printed  essay.  The  description  of  the  ear  of  the  ray  was  given  by 
Geoffrey  in  a Memoir  on  the  Ears  of  Reptiles,  presented  in  1752,  and  printed 
in  1755.] 

f [Camper’s  researches  on  this  subject  were  made  in  the  year  1761 : they 
appeared  first  in  the  Haerlem  Memoirs  for  1762.  He  afterwards  sent  a more 
detailed  memoir  on  the  same  subject  to  the  Academy  of  Sciences  of  Paris  in 
1767,  which  was  printed  in  the  ‘ Recueil  des  Savans  Etrangers,  t.  vii.,’  in  1774. 
He  describes  in  detail  the  organ  of  hearing  of  the  ray,  the  cod,  the  pike,  and  the 
lophius,  with  figures  in  his  style,  i.  e.,  somewhat  vague.  He  added  but  little  to 
that  which  Geoffroy  had  advanced,  except  that  he  denied  too  generally  the  exter- 
nal canal,  and  that  he  speaks  of  an  organ  which  he  terms  tensor  bursx,  which 
seems  only  to  be  an  appendage,  or  rather  a ligament,  more  distinct  in  the  pike 
than  in  most  other  fishes. 

In  the  year  1773,  in  the  17th  vol.  of  the  JVovi  Commentarii  of  St.  Petersburgh, 


OF  THE  ORGAN  OF  HEARING  IN  FISHES. 


299 


organ  in  fishes,  and  had  the  parts  exposed  and  preserved  in  spirits. 
In  some  the  canals  were  filled  with  coloured  injection,  which 
showed  them  to  great  advantage,  and  in  others  were  so  prepared 
as  to  fit  them  to  be  kept  as  dried  preparations.*  My  researches, 
in  that  and  in  every  other  part  of  tlie  animal  ceconomy,  have  been 
continued  ever  since  that  time.  I am  still  inclined  to  consider 
whatever  is  uncommon  in  the  structure  of  this  organ  in  fishes  as 
only  a link  in  the  chain  of  varieties  displayed  in  its  formation  in 
different  animals,  descending  from  the  most  perfect  to  the  most 
imperfect,  in  a regular  progression.f 

As  in  this  age  of  investigation  a hint  that  such  an  organ  existed 
would  be  sufficient  to  excite  a spirit  of  conjecture  or  inquiry,  I was 
aware  that  there  would  not  be  wanting  some  men  who,  whether 
they  only  imagined  the  fact  might  be  true,  or  really  found  it  to  be 
so,  would  be  very  ready  to  assume  all  the  merit  of  the  discovery 
to  themselves.  My  attention  was  more  strongly  called  to  this 
point  by  hearing,  in  conversation,  that  some  anatomists  in  France, 
Germany,  and  Italy,  bad  discovered  the  organ  of  hearing  in  fishes, 
and  intended  to  publish  on  the  subject.  I therefore  thought  that  it 
would  be  only  justice  to  myself  to  deliver  to  the  Royal  Society  a 
short  account  of  that  organ,  a discovery  of  which  I had  made  more 
than  twenty  years  before.  This  account  I shall  reprint  here, 
without  adding  anything  to  what  I had  before  written,  reserving  a 
more  complete  examination  of  this  subject  for  a larger  work,  on 
the  structure  of  animals,  which  I one  day  hope  to  have  it  in  my 
power  to  publish. 

I do  not  intend  to  give  a full  account  of  this  organ  in  any  one 
fish,  or  of  the  varieties  in  different  fishes,  but  only  of  the  organ  in 
general ; those  therefore  who  may  wish  to  pursue  this  branch  of 
the  animal  oeconomy  will  think  it  deficient  perhaps  in  the  descrip- 

Kolreuter  gave  some  very  precise  and  detailed  descriptions  and  figures  of  the  ear, 
in  two  species  of  sturgeon,  the  common  one  {Jicipenser  Slurio,  Linn.),  and  the 
huso  {Jicipenser  Huso,  Linn.). 

Monro  described,  better  than  any  of  his  predecessors  or  successors,  the  external 
ear  of  the  Chondropterygii,  in  his  Anatomy  of  Fishes,  published  in  1785. 

Scarpa  denies  the  external  communication  in  the  ray,  which  Hunter  correctly 
describes  in  the  present  memoir.] 

*I  have  injected  these  parts  in  other  animals,  both  with  wax  and  metals; 
which,  the  bone  being  afterwards  corroded  in  spirit  of  sea-salt,  make  elegant 
casts  of  these  canals. 

f The  preparations  to  illustrate  these  factsa  have  been,  ever  since,  shown  in 
my  collection,  to  both  the  curious  of  this  country  and  foreigners.  In  showing 
whatever  was  new,  or  supposed  to  be  new,  the'ears  of  fishes  were  always  con- 
sidered by  me  as  one  important  article. b 


a [He  here  alludes  to  the  series  of  other  organs  in  his  collection  analogous  to 
those  of  the  ear ; and  it  is  interesting  to  observe  these  incidental  evidences  of  the 
philosophical  tendency  in  Hunter  to  view  the  varieties  of  structure,  which  his 
numerous  dissections  displayed  to  him,  as  modifications  of  one  type,  or  a graduated 
and  connected  chain  of  varieties.] 

b [See  the  Preparations  in  the  Gallery  of  the  Hunterian  Museum,  numbered 
from  1560  to  1574  inclusive.] 


300 


HUNTEK  ON  THE  ANIMAL  CECONOMY. 


live  parts.  If  it  was  a difficult  task  to  expose  this  organ  in  fishes 
I should  perhaps  be  led  to  be  more  full  in  my  description  of  if,  but 
in  I’act  there  is  nothing  more  easy. 

It  may  be  proper  just  to  observe  here,  that  the  class  called  Sepia 
has  the  organ  of  hearing,  though  somewhat  differently  constructed 
from  what  it  is  in  fishes.* 

The  organ  of  hearing  in  fishes  is  placed  at  the  sides  of  the  cavity 
which  contains  the  brain,  but  the  skull  makes  no  part  of  it,  as  it 
does  in  the  quadruped  and  the  bird,  the  organ  being  a distinct  and 
detached  part.  In  some  fishes,  as  in  those  of  the  ray  kind,  the 
organ  is  wholly  surrounded  by  the  parts  composing  the  cavity  of 
the  skull;  in  others  it  is  in  part  within  the  skull,  or  cavity  which 
contains  the  brain,  as  in  the  salmon,  cod,  &c.,  the  skull  projecting 
laterally,  and  forming  a cavity. 

The  organ  of  hearing  in  fishes  appears  to  increase  in  dimensions 
with  the  animal,  and  nearly  in  the  same  proportion,  which  is  not  the 
case  with  the  quadruped,  &c.,  the  organs  being  in  them  nearly  as 
large  in  the  growing  foetus  as  in  the  adult.  Neither  is  its  structure, 
by  any  degree,  so  complicated  in  fishes  as  in  all  those  orders  of 
animals  w'hich  maybe  reckoned  superior,  such  as  quadrupeds,  birds, 
and  amphibious  animals;  but  there  is  a regular  gradation  from  the 
first  of  these  to  fishes. 

It  varies  in  different  genera  of  fishes  ; but  in  all  it  consists  of  three 
curved  tubes,  which  unite  one  with  another  ; this  union  forms  in 
some  only  one  canal,  as  in  the  cod,  salmon,  ling,  &c.,  and  in  others 
a tolerably  large  cavity,  as  in  the  ray  kind.  In  the  jackf  there  is 
an  oblong  bag,  or  blind  process,  which  is  an  addition  to  these  canals, 
and  communicates  with  them  at  their  union.  In  the  cod,  &c.,  this 
union  of  the  three  tubes  stands  upon  an  oval  cavity  ; and  in  the 
jack  there  are  two  ; the  additional  cavities  in  these  fishes  appearing 
to  answer  the  same  purpose  with  the  cavityj  observed  in  the  ray 
or  cartilaginous  fishes,  which  is  at  the  union  of  the  three  canals. 

The  whole  organ  is  composed  of  a kind  of  cartilaginous  substance, 
very  hard  or  firm  in  some  parts,  and  in  some  fishes  crusted  over  with 
a tifin  bony  lamella,  to  prevent  it  from  collapsing;  for  as  the  skull 
does  not  form  any  part  of  these  canals  or  cavities,  they  must  be 
composed  of  a substance  capable  of  keeping  its  form. 

* [This  is  the  first  announcement  of  the  existence  of  an  organ  of  hearing  in  the 
Cephalopoda.  It  differs  from  that  of  fishes  in  the  absence  of  the  semicircular 
canals,  and  exhibits  a simpler  stage  of  structure,  consisting  of  a vestibule,  with 
the  nerve,  fluid,  sacculus,  and  ear-stone  or  otoliilie.  The  low-organized  Cyclos- 
tomous  fishes  manifest  their  character  as  transitional  links  between  the  inverte- 
brate animals  in  several  parts  of  their  structure,  but  more  especially  in  the  organ 
of  hearing.  The  myxine  has  a vestibule,  with  one  canal  extended  from  it.  The 
lamprey  shows  a further  stage  of  complication,  in  having  two  canals  continued 
from  the  vestibule.  All  the  osseous  fishes  have  three  semicircular  canals,  as 
described  in  the  text;  and  the  plagiostomous  cartilaginous  fishes,  as  the  sharks 
and  rays,  exhibit  a higher  type  of  structure,  in  having  the  internal  ear  inclosed 
within  the  parietes  of  the  cranial  cavity,  and  in  the  external  communication  or 
meatus  which  some  of  the  species  present.] 

f [£sox  Lucius,  L.]  \_Sacculus  vestibuU.'] 


OF  THE  ORGAN  OF  HEARING  IN  FISHES. 


301 


Each  tube  describes  more  than  a semicircle,  resembling,  in  some 
sort,  what  we  find  in  most  other  animals,  but  difiering  in  the  parts 
being  distinct  from  the  skull.* 

Two  of  the  semicircular  canals  are  similar  to  one  another,  may 
be  called  a pair,  and  are  placed  perpendicularly ; the  third  is  not 
so  long,  and  in  some  is  placed  horizontally,  uniting  as  it  were  the 
other  two  at  their  ends  or  terminations.  In  the  skate  this  is  some- 
what difierent,  the  horizontal  canal  being  united  only  to  one  of  the 
perpendicular  canals.  The  two  semicircular  canals,  whose  position 
is  perpendicular,  are  united,  forming  one  canal ; at  their  other  ex- 
tremities they  have  no  connection  with  each  other,  but  join  the  ho- 
rizontal one,  near  its  entrance  into  the  common  cavity.  Near  the 
union  of  these  canals  they  are  swelled  out  into  round  bags  ‘ {am.'pullcE)' 
and  become  much  larger. 

In  the  ray  kind  all  these  canals  terminate  in  one  cavity,  and  in 
the  cod  in  one  canal,  placed  upon  the  additional  cavity  or  cavities, 
in  which  there  is  a bone  or  bones.  In  some  there  are  two  bones  ; 
and  in  the  jack,  which  has  two  cavities,  we  find  in  one  of  them,  (the 
accessory  sacculus  of  the  vestibule,)’  two  bones,  and  in  the  other 
‘ (the  ordinary  sacculus  of  the  vestibule,)’  one  ; in  the  ray  there  is 
only  a chalky  substance.f 

In  some  fishes  the  external  communication,  or  meatus,  enters  at 
the  union  of  the  two  perpendicular  canals,  which  is  the  case  with 
all  the  ray  kind,  the  external  orifice  being  small,  and  placed  on  the 
upper  flat  surface  of  the  head  ; but  it  is  not  every  genus  or  species 
of  fishes  that  have  the  external  opening.J 

The  nerves  of  the  ear  pass  outwards  from  the  brain,  and  appear 
to  terminate  at  once  on  the  external  surface  of  the  enlarged  part  of 
the  semicircular  tubes  above  described. § They  do  not  appear  to 
pass  through  these  tubes  so  as  to  get  on  the  inside,  as  is  supposed 
to  be  the  case  in  quadrupeds ; I should  therefore  very  much  suspect 


* The  turtle  and  the  crocodile  have  a structure  somewhat  similar  to  this  ; and 
the  intention  is  the  same,  for  their  skulls  make  no  part  of  the  organ. 

f This  chalky  substance  is  also  found  in  the  ears  of  amphibious  animals. a 
* X [Hunter  had  a drawing  made  of  these  orifices  in  the  monk-fish  {^Squatina 
Angelas,  Dura.),  which  has  been  engraved  and  published  in  the  third  volume  of 
the  Physiological  Catalogue  of  the  Hunterian  Museum,  pi.  xxxiii.  fig.  1,  a.] 

§ [The  acoustic  nerve  comes  off  from  the  brain,  nearly  opposite  the  junction  of 
the  sacculus  with  the  vestibule;  it  sends  off  from  its  upper  part  a filament  to  each 
of  the  semicircular  canals:  this  filament  penetrates  the  ampulla  of  the  canal  to 
which  it  appertains,  and  is  there  lost.  Another  division  of  the  nerve  goes  to  the 
vestibule,  but  by  far  the  greatest  part  of  it  spreads  out  into  a number  of  filaments 
which  form  a very  beautiful  apparatus,  uuder  the  parietes  of  the  sac  which  con- 
tains the  large  stone.] 


? [In  these  it  is  lodged  in  a small  blind  sac,  communicating  with  the  vestibule, 
and  representing  the  cochlea  in  a rudimental  state.  In  the  ray  also,  the  vestibule, 
after  receiving  the  orifices  of  the  semicircular  canals,  opens  into  a large  oval  sac, 
which  gives  off  two  appendages,  one  anterior,  the  other  posterior ; this  sac  is 
analogous  to  the  rudimental  cochlea  in  reptiles,  as  is  also  the  sacculus  vesiibuli 
in  the  osseous  fishes.] 


27 


302 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


that  the  lining  of  the  tubes  in  the  quadruped  is  not  nerve,  but  a kind 
of  internal  periosteum. 

As  it  is  evident  that  fishes  possess  the  organ  of  hearing,  it  becomes 
unnecessary  to  make  or  relate  any  experiment  made  with  living 
fishes,  which  only  tends  to  prove  this  fact ; but  I will  mention  one 
experiment,  to  show  that  sounds  affect  them  much,  and  is  one  of 
their  guards,  as  it  is  in  other  animals.  In  the  year  1762,  when  I 
was  in  Portugal,  I observed  in  a nobleman’s  garden,  near  Lisbon, 
a small  fish-pond  full  of  different  kinds  of  fish.  The  bottom  was 
level  with  the  ground,  the  pond  having  been  made  by  forming  a 
bank  all  round,  and  had  a shrubbery  close  to  it.  Whilst  I lay  on 
the  bank  observing  the  fish  swimming  about,  I desired  a gentleman 
who  was  with  me  to  take  a loaded  gun  and  fire  it  from  behind  the 
shrubs.  The  reason  for  desiring  him  to  go  behind  the  shrubs  was, 
that  there  might  not  be  the  least  reflexion  of  light.  The 
moment  the  report  was  made  the  fish  seemed  to  be  all  of 
one  mind,  for  they  vanished  instantaneously,  raising  a cloud  of 
mud  from  the  bottom.  In  about  five  minutes  afterw’ards  they 
began  to  appear,  and  were  seen  swimming  about  as  before. 

Mons.  Geofl’roi,  who  has  written  on  this  organ,  considers  the  ray 
as  in  the  class  of  reptiles,  and  with  that  idea  has  examined  their 
organ  of  hearing.  He  is  by  no  means  clear  in  his  description,  so 
that  it  is  almost  impossible  to  follow  him  ; yet  it  is  but  doing  him 
justice  to  allow  that  he  has  discovered  what  is  analogous  to  the 
three  semicircular  canals  in  other  animals,  together  with  their  union 
into  one  cavity.  He  mentions  the  chalky  substance  contained  in 
that  cavity,  and  also  the  nerves;  but  it  is  by  no  means  clear  that 
he  was  acquainted  with  the  external  opening  which  leads  to  these 
canals.  He  says,  “ The  entrance  of  the  organ  of  hearing  (by  which 
one  wmuld  suppose  he  means  the  meatus  auditorius  externus)  is  not 
easily  discovered  but  that  which  he  describes  does  not  corres- 
pond with  the  real  situation  of  the  external  communication  ; we 
may  therefore  reasonably  conclude  that  he  is  describing  something 
else.  He  is  not  more  clear  in  his  mode  of  reasoning  on  the  appli- 
cation of  the  parts  to  produce  the  sense  of  hearing.  He  observes 
that  the  organ  of  hearing  is  very  imperfee.t  in  this  species  of  anim.als, 
but  supposes  this  to  be  compensated  by  the  medium  in  which  they 
live,  and  by  which  sound  is  conveyed  to  them,  being  more  dense 
than  that  of  the  air,  by  which  sound  is  communicated  to  animals 
living  on  the  land  ; and  of  this  idea  he  is  certainly  the  author. 
Mons.  Geoffroi  cannot  indeed  be  said  to  have  given  a perfect 
account  of  the  organ  of  hearing  in  fishes,  yet  on  the  whole  he  should 
be  considered  as  a discoverer;  for  though  he  only  made  his  obser- 
vations on  the  ray,  as  belonging  to  the  class  of  reptiles,  yet  as  it 
may  be  properly  considered  of  the  fish  kind,  he  has  a just  claim  to 
that  credit.  Had  I formerly  been  acquainted  with  this  author’s 
researches  and  pretensions,  I should  not  have  claimed  that  to  which 
I had  not  a prior  right : nor  should  I have  held  the  discovery  of 
the  external  communication  alone,  an  object  of  consequence  enough 
to  induce  me  to  dispute  the  honour  with  Mons.  Geoffroi. 


OF  ABSORPTION  BY  VEINS. 


3oy 


In  lookins:  over  the  works  of  the  different  authors  who  have 
treated  of  the  organ  of  hearing  in  fishes,  I find  from  a passage  in 
Willoughby,* * * §'  who  published  prior  to  Mons.  Geoffroi,  and  indeed  is 
quoted  by  him,  that  my  claim,  even  to  the  discovery  of  the  external 
opening,  is  not  so  strong  as  I believed  it  to  be,  as  he  mentions  an 
external  orifice  in  the  skate  contiguous  to  what  he  supposes  the 
organ  of  hearing  in  that  fish.  If  what  he  alludes  to  is  really  the 
external  opening  of  the  ear,  it  gives  him  a prior  claim  to  the  disco- 
very of  that  part  of  the  organ,  although  from  his  account,  he  does 
not  seem  to  have  been  acquainted  with  the  organ  itself ; for,  as  in 
describing  the  external  ear  of  the  thornback,  he  has  evidently  mis- 
taken the  nose  of  it,  of  which  he  gives  a tolerably  full  account,  it  is 
very  obvious  that  he  was  ignorant  of  the  opening  into  the  ear.f 
Although  Professor  Camper  published  an  account  of  the  organ 
of  hearing  in  fishes  so  late  as  1774,  he  did  not  seem  at  that  time  to 
have  been  acquainted  with  the  external  opening  of  the  ear  in  the 
ray.  After  giving  a description  of  the  organ  of  hearing  in  the  pike, 
he  makes  some  general  observations  on  the  similarity  of  this  organ 
in  other  fishes,  but  excepts  the  shark  and  ray.J  This  exception  we 
might  suppose  alluded  to  the  auditory  canal,  but  further  on  he 
explains  what  is  meant  by  this  exception,  and  does  not  mention  the 
external  opening  in  the  ray,  from  which  we  may  fairly  conclude 
that  he  was  not  acquainted  with  it.§ 


30.  OF  ABSORPTION  BY  ^rEINS.H 

[Dr.  Hunter  introduces  the  account  of  his  brother’s  experiments  on  this  subject  as 

follows.] 

In  both  my  courses  of  the  winter  1759-60,  I went  so  far  as  to 
say,  I believed  that  the  red  veins  did  not  absorb ; and  gave  my  rea- 

* Willughbeii  Historia  Piscium,  Oxonii  1686,  lib.  iii.  cap.  viii. 

f Lib.  iii.  cap.  xiv. 

4;  “ II  est  tres-vraisemblable  que  toutes  les  autres  especes  de  poissons,  tant 
malacopterygii  qu’  acanthopterygii,  aussi-bien  que  les  branchiostegi  & les  c/ion- 
dropterygii  d’Artedi,  a I’exception  des  squales  & des  raies,  ont  I’organe  de  I’ouie 
construit  a peu  pres  de  la  meme  faqon  ; je  n’excepte  pas  I’esturgeon,  quoique  M. 
Klein,  ibid,  ait  donne  la  description  du  conduit  auditif,page  V^,  figure  A,  Tab.  2. 
b ; ce  poisson  etant  rare  parmi  nous,  je  n’ai  eu  occasion  de  I’examiner  qu’une 
seule  fois  sans  avoir  trouve  ce  conduit.”  Memoirs  Etrangers  de  I’Academie  des 
Sciences,  1774,  tom.  6,  page  190. 

§ “ Au  contraire,  les  chiens  de  mer,  lesg-a/ersde  Rondelet  & les  poissons  qu’il 
a decrits,  lib.  XII. ; les  sgualis  d’Artedi  & les  raies,  ont  bien  I’organe  a peu  pres 
de  la  meme  composition,  mais  il  est  enferme  dans  une  caisse  tout  osseuse  ou 
cartilagineuse,  ce  qui  ne  fait  pas  une  difference  essentielle  ; ils  entendent  done 
comme  le  eglefins,  les  morues,  les  baudro)’es  & les  brochets,  en  un  mot  comme 
tous  les  autres  poissons  non  amphibies:  M.  Geoffroi  s’est  trompe  en  comparant 
leurs  organes  avec  celui  de  reptiles,  tels  que  la  vipere,  les  lezards,&c.  qui  enten- 
dent le  son  comme  les  quadrupedes,  les  oiseaux  &,  les  amphibies  aquatiques, 
savoir  par  le  moyen  de  Pair  & d’un  tambour,  comme  j’ai  dessein  de  le  proiiver 
dans  une  autre  occasion.”  Memoires  Etrangers  de  PAcademie  des  Sciences, 
1774,  tom.  6,  page  190. 

II  [Medical  Commentaries,  Part  I.,  p.  39.] 


304 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


sons  for  thinking  so ; and  in  different  parts  of  my  lectures  I used 
to  treat  of  the  transudation  and  absorption  of  fluids  in  animal  bodies 
in  the  following  manner: 

“ I have  often  considered  with  myself  how  the  interstitial  fluid 
gets  into  the  smaller  and  greater  cavities  of  our  bodies ; how  the 
water  of  an  anasarca,  for  instance,  gets  into  the  cellular  membrane. 
The  common  opinion,  I think,  is,  that  there  are  everywhere  exhalant 
arteries,  which  open  and  terminate  on  the  sujierficies  of  such  cavi- 
ties, and  throw  out  the  watery  fluid  which  they  contain.  But  for 
my  own  part,  I cannot  help  believing  that  it  is  entirely  by  transuda- 
tion through  the  coats  or  sides  of  the  vessels.  My  reasons  for 
thinking  so  are  these  : 

“First,  so  far  as  I can  find,  all  the  arguments  of  the  latest  and 
best  anatomists,  taken  from  injecting  the  arterial  system  in  dead 
and  living  bodies,  only  prove  that  a thin  fluid  passes  readily  from 
the  arteries  into  the  interstices  of  parts.  They  do  not  prove  the 
existence  of  exhaling  branches  more  than  they  prove  transudation. 

“ In  the  second  place,  the  phenomena  of  injection’s,  so  far  as  I 
have  been  able  to  make  observations,  agree  better  with  the  notion 
of  transudation  than  with  that  of  exhaling  arteries.  I have  had 
great  experience  of  injections,  and  I have  made  experiments  with 
all  sorts  of  fluids  injected  into  the  arteries  and  veins  of  dead  bodies. 
I have  always  observed  that  subtile  and  penetrating  fluids  pass  with 
ease  from  the  arteries  into  the  cavity  of  the  intestines,  and  into  the 
cellular  membrane  in  any  part  of  the  body:  such  fluids  are  water, 
gum-water,  whites  of  eggs  strained,  glue,  isinglass  dissolved  in 
water  or  spirits,  any  fluid  oil,  melted  butter  or  axunge,  &c.  But 
when  these  fluids  were  coloured  with  vermilion  I always  observed 
that  none  of  the  vermilion  passed  out  of  the  arterial  system  but 
when  there  were  manifest  appearances  of  extravasation  and  rupture 
of  the  vessels:  I never  observed  vermilion  pass  into  the  cavity  of 
an  intestine  from  the  mesenteric  arteries,  without  seeing  a hundred 
ruptures  and  extravasations  in  the  villi  of  the  gut.  All  this  looks 
as  if  the  fluid  oozed  through  the  coats  rather  than  was  poured  out 
by  the  branches  of  arteries. 

“ In  the  third  place,  I have  observed  that  the  cellular  membrane 
is  not  so  immediately  filled  by  injecting  the  arteries  ; it  requires 
some  time,  and  I have  plainly  seen,  when  I have  let  an  injected  part 
lie  by  a little  while,  that  the  cellular  membrane  became  gradually 
more  loaded  as  the  arterial  system  became  more  empty : a strong 
argument,  in  my  mind,  that  it  got  out  of  the  arteries  by  transudation. 

“ In  the  fourth  place,  w'ater  and  even  red  blood  soaks  through 
all  our  vessels  and  membranes  in  dead  bodies;  as  you  may  see  by 
steeping  the  apex  of  a heart  well  w’ashed,  or  the  convolution  of  a 
piece  of  fresh  intestine  in  clear  water;  in  both  cases  the  w'ater  will 
become  bloody, 

“ But  still  it  is  said  that  in  all  these  cases  the  fluids  pass  by  fine 
exhaling  vessels,  though  these  vessels  cannot  be  seen.  To  this  I 
answ'er  that  if  our  interstitial  fluid  was  of  a strong  marked  colour, 


OF  ABSORPTION  BY  VEINS. 


305 


we  should  then  by  dissection  be  able  to  observe  whether  it  was 
poured  out  by  small  arteries,  or  whether  it  soaked  through  the 
natural  pores  in  the  coats  of  vessels.  Now,  very  fortunately  for  us 
in  this  dispute,  there  is  one  such  fluid  in  the  body : it  is  the  bile. 
Its  colour  is  pretty  deep,  and  very  different  from  anything  that  lies 
near  the  gall-bladder.  No  man  can  have  opened  any  number  of 
bodies  without  allowing  that  the  gall  does  pass  through  all  the  coats 
of  the  gall-bladder,  and  pervades  the  substance  of  the  neighbouring 
parts,  not  by  exhaling  nor  by  inhaling  vessels,  but  by  manifest  tran- 
sudation or  soaking. 

“ It  might  be  asked,  why  the  red  blood  does  not  transude  through 
the  vessels  in  living  bodies  ; for  I think  it  certainly  does  not.  In 
answer  to  this  it  may  be  said  that  our  fibres  and  vessels  have  per- 
haps some  degree  of  tension  and  firmness  in  life  which  they  lose 
with  life;  and  it  must  be  observed  too,  that  in  proportion  as  the 
blood  purifies  it  becomes  thinner ; whence  we  see,  in  opening  a 
putrid  body,  all  the  cavities  more  or  less  filled  with  a bloody  water, 
and  all  distinction  of  colour  in  the  muscles  and  cellular  membrane 
quite  lost.  But  what  I suppose  to  be  the  principal  reason  that  red 
blood  does  not  transude  through  the  vessels  in  living  bodies  is  its 
glutinous  quality,  its  thickness  while  it  is  equally  mixed  up  with  its 
coagulating  part.  That  part  coagulates  as  certainly  as  the  blood 
stagnates  even  in  living  bodies;  and  when  the  universal  stagnation 
happens  in  death,  this  part  of  the  blood  collects  itself  into  irregular 
polypi  and  coagulations  all  over  the  body,  and  the  rest  of  the  blood 
is  no  longer  the  thick  viscid  fluid  it  was  before,  but  rather  a bloody 
serum,  that  will  ooze  through  all  the  vessels  and  membranes.” 

Such  were  my  notions  of  the  source  of  oar  interstitial  fluid. 
With  regard  to  its  absorption,  I was  of  opinion  that  Nature  had 
provided  a system  on  purpose,  viz.,  the  lymphatics.  I considered 
these  vessels  and  the  lacteals  as  an  appendage  to  the  venal  system, 
by  which  the  stores  were  brought  in  for  supplying  the  circulation; 
and  the  glands  and  secretory  vessels  all  over  the  body  I considered 
as  an  appendage  to  the  arterial  system,  by  which  the  proper  sepa- 
rations were  made,  and  the  redundancies  thrown  ofl’. 

My  only  doubt  was  whether  the  veins  did  or  did  not  absorb  a 
certain  quantity,  especially  in  the  intestines.  From  my  own  obser- 
vations on  injections  I should  have  concluded  that  they  did  not, 
and  that  there  was  no  passage  for  liquors  between  an  intestine 
and  the  mesenteric  veins  otherwise  than  by  transudation.  But 
authors  of  the  best  credit  had  given  such  arguments  and  experi- 
ments in  favour  of  absorption  by  veins,  that  I dared  not,  even  in  my 
own  mind,  determine  the  question. 

At  this  time  my  brother  was  deeply  engaged  in  physiological 
inquiries,  in  making  experiments  on  living  animals,  and  in  prose- 
cuting comparative  anatomy  with  great  accuracy  and  application. 
It  is  well  known  that  I speak  of  him  with  moderation  when  I say 
so.  He  took  the  subject  of  absorption  into  his  consideration,  and 

27* 


306 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


from  all  his  observations  was  inclined  to  believe  that  in  the  human 
body  there  was  one,  and  but  one,  system  of  vessels  for  absorption. 
He  knew  so  well  that  many  things  had  been  asserted  by  one  person 
after  another  which  were  not  true,  that  so  many  mistakes  had  been 
made  from  inattention,  so  many  errors  introduced  from  other 
causes,  that  he  could  easily  suppose  the  veins  might  not  perhaps 
absorb,  after  all  the  demonstrations  that  had  been  given  of  the 
fact ; and  therefore  was  determined  to  see  how  far  this  point  could 
be  cleared  up  by  plain  experiments  and  observations.  With  that 
intention  he  made  the  following  experiments,  in  my  presence  and  in 
the  presence  of  a number  of  gentleman,  who  all  of  us  assisted  him, 
and  made  our  own  observations  upon  what  passed  before  us.  I 
shall  quote  the  experiments  from  him,  and  can  bear  testimony  to 
the  fairness  with  which  they  were  made  and  with  which  they  are 
here  related. 

“ Animal  First. — Experiment  I.  On  the  3d  of  November,  1758,”* 
says  he,  “ I opened  the  belly  of  a living  dog.  The  intestines  rushed 
out  immediately.  I exposed  them  fully;  and  we  observed  the  lacteals 
filled  with  a white  liquor  at  the  upper  part  of  the  gut  and  mesentery  ; 
but  in  those  which  came  from  the  ileon  and  colon  the  liquor  was 
transparent. 

“ I tied  up  the  mesenteric  artery  and  vein  that  was  going  to  about 
half  a foot  of  intestine,  and  put  a tight  ligature  upon  the  upper  part 
of  the  intestine,  including  a little  of  the  mesentery  ; then  emptied 
that  part  of  the  gut  by  squeezing  it  downwards,  and  put  a similar 
ligature  upon  the  lower  part  of  the  gut.  In  the  next  place,!  made 
a small  hole  in  the  upper  end  of  this  part  of  the  gut,  and  by  a funnel 
poured  in  some  warm  milk,  and  confined  it  by  making  a third 
ligature  upon  the  gut  close  to  this  hole.  These  ligatures  prevented 
the  circulation  of  blood  in  this  part  of  the  bowel.  Lastly,  I punc- 
tured the  vein  beyond  the  ligature  that  had  been  made  upon  the 
mesenteric  vessels,  and  by  gently  stroking  with  the  end  of  the  finger 
soon  emptied  it  of  its  blood. 

“Experiment  II.  I immediately  after  this  made  the  same  experi- 
ment, and  in  the  same  manner,  on  a part  of  the  intestine  lower 
down,  where  the  lacteals  were  filled  with  a transparent  liquor. 

“ In  the  first  experiment  the  lacteals  continued  to  be  filled  with 
a milky  or  white  fluid : in  the  second,  the  lacteals,  which  before 
contained  only  a transparent  lymph,  were  presently  filled  with  white 
milk. 

“ In  both  these  experiments  we  could  not  observe  that  the  least 
white  fluid  had  got  into  the  veins.  After  attending  to  these  appear- 
ances a little  while,  I put  all  the  bowels  into  the  abdomen  for  some 
time,  that  the  natural  absorption  might  be  assisted  by  the  natural 
warmth;  then  took  out  and  examined  attentively  the  twm  parts  of 
the  gut  and  mesentery  upon  which  the  experiments  had  been  made  : 

* In  presence  of  Doctors  Clayton,  Fordyce,  and  Michaelson,  and  Messrs. 
Blount,  Jones,  Churcliill,  and  Richardson. 


OF  ABSORPTION  BY  VEINS. 


307 


but  the  lacteals  were  still  filled  with  milk,  and  there  was  not  the 
least  appearance  of  a white  fluid  in  the  veins  ; on  the  contrary,  what 
little  blood  was  in  them  was  just  as  thick  and  as  deep-coloured  as 
in  the  other  veins,  and  when  squeezed  out  from  them  coagulated  as 
the  blood  of  other  veins. 

“ Experiment  III.  I tied  up  and  filled  another  piece  of  the  intes- 
tine with  milk  in  the  same  manner,  but  did  not  make  a ligature  upon 
the  mesenteric  vessels,  leaving  a free  circulation  in  the  part.  We 
looked  very  attentively  at  the  colour  of  the  blood  in  the  vein  of  that 
part,  both  with  our  naked  eyes  and  with  glasses : we  compared  it 
with  that  in  the  artery  and  in  the  neighbouring  veins,  but  could  not 
observe  that  it  was  lighter-coloured,  nor  that  it  was  milky,  nor  that 
there  was  any  difference  whatever. 

Experiment  IV.  Lastly,  we  took  that  part  of  the  gut  which  was 
filled  with  milk  in  the  first  or  second  experiment,  and  squeezed  and 
pressed  it  very  gradually,  in  order  to  see  whether  any  milk  would 
by  these  means  pass  into  the  empty  mesenteric  veins.  This  we 
did  gradually,  with  more  and  more  force,  till  the  gut  at  last  burst; 
but  stilt  there  was  not  the  least  appearance  of  anything  milky  in 
the  veins. 

‘‘Animal  Second. — Experiment  I.  November  13,  1758,*  I 
opened  the  abdomen  of  a living  sheep,  which  had  eat  nothing  for 
some  days,  and  upon  exposing  the  intestines  and  mesentery  we 
observed  the  lacteals  were  visible,  but  contained  only  a transparent 
watery  fluid.  I made  a hole  in  the  intestine  near  the  stomach,  and 
by  a funnel  poured  in  some  thin  starch,  coloured  with  indigo,  so  as 
to  fill  several  convolutions  ; then  tied  up  the  whole  in  the  gut,  and 
put  all  the  bowels  into  the  abdomen  for  some  time.  Upon  taking 
them  out  after  this  we  observed  all  the  lacteals  of  that  part  filled 
with  a fluid  of  a fine  blue  colour.f  We  thought  at  first  that  the 

* In  presence  of  Doctors  Wren,  Fordyce,  and  Michaelson,  and  Messrs.  Blount, 
Tickell,  Churchill,  Paterson,  and  SUeette. 

j-  [Martin  Lister,  in  1682,  injected  twelve  ounces  of  the  tincture  of  indigo  into 
the  small  intestines  of  a living  and  fasting  dog.  At  the  time  of  the  experiment 
there  “ was  not  the  least  appearance  of  lacteal  veins  in  the  mesentery  after 
full  three  hours  the  mesentery  was  examined,  and  many  lacteals  were  found  of 
an  azure  colour;  and  some  of  the  biggest  of  them  being  cut,  a thick  bluish  chyle 
was  seen  to  issue  forth.  (Phil.  Trans.,  vol.  xiii.,  p.  9.)  The  conclusion  which 
Lister  drew  from  this  experiment  with  reference  to  the  power  of  the  lacteals  to 
absorb  extraneous  matters  along  with  the  chyle,  was  opposed  in  his  time  by  some 
writers,  and  it  was  stated  “ that  people  may  be  deceived  with  blue  tinctures,  for 
this  is  the  natural  colour  of  these  lacteals  when  they  are  almost  or  altogether 
empty.”  See  Phil.  Trans.,  No.  275,  October,  1701,  p.  996. 

In  order  to  try  the  value  of  this  objection.  Dr.  Wra.  Musgrave  instituted  the 
following  experiments : 

“ Feb.  1682-3.  I injected  into  the  jejunum  of  a dog,  that  had  for  a day  before 
but  little  meat,  about  twelve  ounces  of  a solution  of  indigo  in  fountain  water,  and 
after  three  hours,  opening  the  dog  a second  time,  1 observed  several  of  the  lacteahs 
of  a bluish  colour,  which,  upon  stretching  of  the  mesentery,  did  several  times 
disappear,  but  was  most  easily  discerned  when  the  mesentery  lay  loose;  an 
argument  that  the  bluish  colour  was  not  properly  of  the  vessel,  but  of  the  liquor 
contained  in  it. 

“ A few  days  after  this,  repeating  the  experiment  in  another  company,  with  the 


308 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


blood  in  the  veins  of  this  part  was  of  a darker  colour,  but  on  com- 
paring it  carefully  with  that  in  the  other  veins  it  was  manifestly 
the  same. 

“ Experiment  II.  I opened  a vein  upon  this  part  of  the  mesen- 
tery, and  catched  a table  spoonful  of  its  blood.  I set  it  by  to  con- 
geal and  separate  into  its  coagulum  and  serum.  On  the  next  day 
and  the  day  after  tliat  I examined  the  colour  of  the  serum,  but  it 
had  not  the  least  bluish  cast. 

“Experiment  III.  I fixed  an  injecting  pipe  in  an  artery  of  the 
mesentery,  where  the  intestine  was  filled  with  the  blue  starch,  and 
tied  up  all  communications  both  in  the  mesentery  and  intestine  (as 
in  Animal  First,  Exper.  I.),  but  left  the  corresponding  vein  free; 
then  I injected  warm  milk  by  the  artery  till  it  returned  by  the  vein, 
and  continued  doing  so  till  all  the  blood  was  washed  away,  and  the 
vein  returned  a bright  white  milk.  This  was  done  with  a view  of 
seeing  if  the  milk  in  the  vein  acquired  any  bluish  cast,  but  there 
was  no  perceptible  dilference  between  the  arterial  and  venal  milk. 

“ Experiment  IV.  After  this  I opened  the  vein  with  a lancet, 
and  discharged  most  of  the  milk,  then  put  a ligature  upon  both  the 
artery  and  vein,  and  waited  some  time  to  see  if  they  would  fill, 
but  they  did  not,  nor  did  the  remaining  contents  of  the  vein  acquire 
the  least  bluish  cast.  Then  I opened  the  gut  at  this  part,  but  we 

solution  of  stone-blue  in  fountain  water,  and  on  a dog  that  had  been  kept  fasting 
thirty-six  hours,  1 saw'  several  of  the  lacteals  become  of  aperfect  blue  colour  within 
very  few  minutes  after  the  injection  : for  tliey  appeared  so  before  I could  sew  up 
the  gut.  At  about  the  beginningof  March  follow’ing,  having  kept  a spaniel  fasting 
thirty-six  hours,  and  then  syringing  a pint  of  a deep  decoction  of  stone-blue  with 
common  water  into  one  of  the  small  guts,  and  after  three  hours  opening  the  dog 
again,  I saw  many  of  the  lacteals  of  a deep  blue  colour.  Several  of  them  were 
cut,  and  aflbrded  a blue  liquor  (some  of  the  decoction),  running  forth  on  the 
mesentery. 

“After  this  I examined  the  ductus  thoracicus  (on  which,  together  with  other 
vessels  near  it,  I had  upon  my  return  made  a ligature),  and  saw  the  receptaculum 
chyli  and  that  ductus  of  a bluish  colour,  not  so  blue  indeed  as  the  lacteals,  from 
the  solution  mixing  in  and  near  the  receptaculum  with  lympha,  but  much  bluer 
than  the  ductus  uses  to  be,  or  than  the  lymphatics  under  the  liver  (with  which  I 
compared  it)  were.  1 trusted  not  my  own  eyes  in  any  one  of  these  experiments, 
but  in  each  of  them  had  the  company  and  assistance  of  several  physicians,  who 
all  agreed  with  me  as  to  the  colouring  of  the  lacteals.”  (Phil.  Trans.,  No.  275, 
October,  1701.) 

The  same  objection,  the  force  of  which  was  invalidated  by  the  experiments  of 
Musgrave,  has  been  in  recent  times  urged  against  ibe  experiments  of  Hunter, 
related  in  the  text ; but  it  is  obvious  that  it  cannot  apply  where  care  is  taken  to 
observe  the  colour  or  appearance  of  the  empty  or  transparent  lacteals  before  throw- 
ing the  coloured  fluid  into  the  intestine,  and  to  contrast  that  appearance  of  the 
lacteals  with  the  colour  which  they  present  after  the  experiment  has  been  per- 
formed. Now  this  precaution  Hunter  invariably  adopted. 

With  reference  to  the  experiments  on  the  lacteals  recorded  in  the  early  numbers 
of  the  Philosophical  Transactions,  it  may  be  observed  that  they  differ  from  those 
of  Hunier  in  the  absence  of  observations  and  modifications  which  the  latter 
physiologist  combined  with  them,  in  order  to  test  the  share  which  the  veins 
might  take  in  the  absorbing  processes; — a question  which  does  not  appear  to 
have  occupied  the  attention  of  either  Lister  or  Musgrave.] 


OF  ABSORPTION  BY  VEINS. 


309 


could  not  observe  any  appearance  of  the  milk  having  got  into  the 
cavity  of  the  intestine. 

“ Experiment  V.  I filled  another  part  of  the  intestine  with  milk. 
All  that  we  observed  after  doing  this  was,  that  the  lacteals  became 
fuller,  though  not  of  a white  colour,  and  the  veins  remained  of  the 
same  complexion. 

“Experiment  VI.  I fixed  a pipe  into  the  vein  of  the  mesentery, 
and  injected  milk  towards  the  intestine,  to  see  if  any  would  pass 
into  the  cavity  of  the  gut;  but  presently  innumerable  extravasations 
happened,  so  that  the  experiment  was  fruitless. 

“ Experiment  VII.  I fixed  a pipe  into  an  artery,  and  tied  up  the 
vein  and  all  the  communications;  then  injected  milk  for  some  time 
into  the  artery  till  the  vein  became  quite  turgid  and  tight ; this 
was  continued  for  some  little  time,  and  with  as  much  force  as  we 
thought  the  vessels  would  bear  without  bursting ; then  we  opened 
the  intestine  at  that  part,  and  there  was  no  appearance  of  milk  in 
its  cavity. 

“Experiment  VIII.  I took  a piece  of  the  intestine  that  was  quite 
empty  and  clean,  and  filled  it  with  warm  water.  The  returning 
blood  in  the  vein  of  this  part  appeared  not  at  all  diluted  or  thinner 
than  in  the  other  veins.  Then  I tied  up  the  artery  and  all  the  com- 
munications, and  attended  to  the  state  of  the  vein  for  some  time ; 
it  did  not  grow  more  turgid,  nor  did  its  blood  become  more  watery, 
nor  w^as  there  any  appearance  whatever  of  the  water’s  having  got 
into  the  veins. 

“ The  animal  was  quite  alive  all  the  time  of  our  making  these 
experiments  and  observations,  which  lasted  from  one  o’clock  till 
half  an  hour  after  three.  I chose  a sheep  rather  than  a dog,  both 
because  the  animal  was  much  larger,  and  therefore  its  mesenteric 
vessels  were  fitter  for  being  easily  injected,  and  besides,  because  it 
is  much  more  patient  and  quiet.  These  advantages  we  were  all 
sensible  of  when  we  made  the  experiments. 

“ Animal  Third. — June  22d,  1759.  We  repeated  most  of  these 
experiments  on  another  sheep,  to  see  if  the  effect  would  be  the 
same,  but  in  this  animal  the  viscera  were  diseased,  inflamed,  and 
thickened  in  most  parts,  so  that  the  experiments  were  much  less 
successful,  less  satisfactory,  and  conclusive.  After  injecting  milk 
into  the  mesenteric  artery  for  some  time,  and  allowing  it  to  return 
by  the  vein,  we  opened  that  part  of  the  intestine  which  had  been 
previously  emptied,  and  found  in  it  a watery  fluid  of  a whitish  cast, 
as  if  a few  drops  of  milk  had  been  mixed  with  it. 

‘^Animal  Fourth. — In  July,  1759,*  I repeated  most  of  the  experi- 
ments related  in  article  Animal  Second,  upon  another  sheep.  The 
effect  of  all  of  them  was  so  nearly  the  samje  that  I need  not  be 
particular. 

“ I shall  only  observe,  that  when  the  intestine  was  filled  with 
starch-water  and  indigo,  and  milk  injected  by  the  artery  till  the 

* In  presence  of  Doctors  Macaulay,  Ramsey,  and  Michaelson,  and  Messrs. 
Edwards  and  Tomlinson. 


310 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


vein  was  washed  clean  of  blood,  and  a ligature  put  upon  the  artery 
•and  vein,  so  as  to  leave  them  about  half  full  of  pure  white  milk, 
after  waiting  more  than  half  an  hour  we  could  not  observe  that  the 
vein  was  in  the  least  more  filled  or  turgid,  nor  had  the  milk  in  the 
veins  acquired  the  least  of  a bluish  cast,  not  even  in  the  small  veins 
upon  the  gut  itself,  where  we  should  suppose  the  absorbed  liquor 
must  have  been  apparent  if  any  had  been  taken  up  by  the  veins 
from  the  cavity  of  the  intestine. 

“After  the  animal  was  dead  I blowed  into  a mesenteric  vein,  and 
the  air  found  a passage  into  the  cavity  of  the  gut ; though  in 
making  the  experiment  when  the  animal  was  alive,  I could  not  force 
the  milk  by  injection  from  the  vein  into  the  gut. 

“ Animal  Fifth. — If  any  animal  could  be  supposed  a fitter  subject 
for  such  experiments  than  a sheep,  it  would  be  an  ass.  He  is  not 
so  large  nor  so  strong  but  that  he  may  be  managed  ; he  is  patient 
in  the  greatest  degree  ; his  mesentery  and  vessels  being  larger,  it 
is  so  much  more  easy  to  fix  injecting  pipes,  make  ligatures,  &lc.  ; 
and,  what  is  a very  great  advantage  in  making  such  experiments, 
his  mesentery  is  very  thin,  without  fat,  so  that  the  vessels  are 
conspicuous  and  distinct.  Hence  it  is  easy  to  separate  the  artery 
from  the  vein,  to  fix  pipes,  to  tie  up  anastomosing  vessels  by  a 
needle,  &c. 

“ Therefore  I got  an  ass,  and  on  the  24th  of  August,  1759,^  put 
him  upon  his  back  in  an  open  garden,  and  tied  him  fast  to  four 
stakes  drove  into  the  ground,  then  opened  his  abdomen,  &c. 

“ Experiment  I.  I poured  a solution  of  musk  in  warm  water  into 
a piece  of  the  intestine,  and  confined  it  there  by  two  ligatures.  In 
doing  this  the  animal  struggled,  and  a little  of  the  liquor  was  spilt 
upon  the  outside  of  the  intestine  and  mesenter}n 

“After  wailing  a little  while,  I opened  with  a lancet  some  lac- 
teals  of  this  part,  which  were  full  of  a watery  fluid,  and  catched  a 
little  of  their  contents  in  a small  spoon.  It  smelled  strongly  of  the 
musk,  and  though  it  could  hardly  be  doubted  that  the  musk  had 
been  taken  up  from  the  intestine  by  absorption,  yet  as  some  of  the 
musk-solution  had  been  spilt  upon  the  external  surface  of  the  parts, 
and  as  it  was  impossible  to  collect  the  lymph  from  the  lacteals 
without  resting  the  edge  of  the  spoon  upon  the  mesentery,  the  smell 
of  the  spoon  might  be  owing  to  that  circumstance. 

“After  this  1 wiped  a vein  upon  the  mesentery  very  clean,  and 
opened  it  with  a lancet : a gentleman  who  had  kept  out  of  the  way 
of  the  musk  came  immediately  with  a clean  spoon,  and  filled  it 
from  the  stream  of  blood  without  touching  any  part  of  the  animal, 
and  carried  it  directly  off,  but  it  had  not  the  least  smell  of  musk. 

“ Experiment  II.  We  poured  some  starch-water,  made  very  blue 
with  indigo,  into  a part  of  the  gut  in  the  same  manner  as  in  some 
of  the  former  experiments,  tied  the  vein  and  artery  of  this  part, 
then  punctured  the  vein  close  to  the  ligature,  and  pressed  out  almost 

* In  presence  of  Doctors  Macaulay  and  Michaelson,  and  of  Messrs.  Edwards, 
White,  and  Gee. 


OF  ABSORPTION  BY  VEINS. 


311 


all  the  blood ; then  tied  up  the  empty  vein,  and  put  all  into  the  cavity 
of  the  belly  for  a quarter  of  an  hour.  After  that  we  examined  the 
part,  found  the  lymphatics  very  turgid,  as  the  fluid  could  not  pass 
through  them  towards  the  thoracic  duct  on  account  of  the  ligatures 
made  upon  the  mesenteric  vessels;  but  we  found  the  veins  of  this 
part  empty,  except  indeed  that  a little  blood  had  got  into  them  from 
the  neighbouring  vessels,  which,  from  the  appearance,  had  evi- 
dently passed  the  ligatures  tied  round  the  ends  of  the  gut,  a circum- 
stance which  it  is  very  difficult  to  obviate. 

“ Experiment  III.  I next  repeated  the  Third  Experiment  of  Ani- 
mal Second  exactly  in  the  same  manner,  and  precisely  with  the 
same  effect. 

“Experiment  IV.  Then  I repeated  the  Fourth  Experiment  of 
Animal  Second,  and  the  effect  was  still  the  same. 

“ N.  B.  It  may  not  be  amiss  to  observe  that  the  lacteals  continued 
to  absorb  the  bluish  liquor  all  this  time,  even  at  the  part  upon 
which  this  Fourth  Experiment  was  made,  where  the  nerves  must 
necessarily  have  been  tied  up  with  the  artery. 

“ Experiment  V.  I squeezed  a piece  of  the  intestine  so  as  to 
empty  it  as  entirely  as  well  might  be,  then  tied  up  all  the  lateral  com- 
munications of  the  vessels,  and  injected  warm  milk  into  the  mesen- 
teric vein  till  it  returned  by  the  artery,  and  continued  this  operation 
for  some  time  after  all  the  blood  was  washed  out.  Then  I opened 
that  part  of  the  intestine  through  its  whole  length,  and  found  it  quite 
empty. 

“ I made  this  experiment  again  upon  another  part  of  the  intestine, 
in  the  same  manner,  and  exactly  with  the  same  success.” 

Here  is  a new  doctrine  proposed  in  physiology,  viz.,  that  the  red 
veins  do  not  absorb  in  the  human  body.  The  fair  inquirer  after 
truth  will  be  convinced,  by  the  observations  which  occurred  to  me, 
that  the  common  opinion,  that  they  do  absorb,  is  supported  by 
some  proofs  that  are  at  least  doubtful  or  equivocal,  and  that  the 
other  opinion  is  not  without  plausibility;  and  he  must  allow  that 
my  brother’s  experiments  render  it  highly  probable. 


[In  attempting  to  form  a correet  estimate  of  the  merits  of  iNIr  Hunter 
as  a discoverer  in  reference  to  the  absorbent  system,  it  becomes  necessary, 
in  the  first  place,  to  distinguish  between  tlie  discovery  of  the  vessels 
themselves,  whether  lacteals  or  lymphatics,  and  that  of  their  functions 
and  anatomical  relations  to  the  other  parts  of  the  vascular  system. 

With  respect  to  the  Mammalia,  it  is  scarcely  necessary  to  observe  that 
the  existence  of  both  lacteals  and  lymphatics  had  been  determined  in  that 
class  long  before  the  time  of  Dr.  William  Hunter. 

The  discovery  of  the  lacteals  by  Asellius  was  first  made  publicly 
known  in  1628  ; and  that  of  the  tlioracic  duct  by  Pecquet  in  1651. 

In  1652  our  countryman  Joliff,  having  placed  a ligature  round  the 
spermatic  cord,  saw,  upon  squeezing  the  testicle,  that  certain  vessels, 
which  he  termed  ‘ vasa  lymphatica,’  became  turgid  ; he  did  not,  however, 


312 


HUNTER  ON  THE  ANIMAL  OECONOMY. 


himself  publish  this  observation,  and  it  might  never  have  seen  tlie  light, 
had  not,  in  the  meanwhile,  the  attention  of  the  anatomical  world  been 
drawn  to  the  lymphatic  vessels  by  Bartholinus,  an  illustrious  philosopher 
of  Denmark,  in  1651,  and  by  Rudbeck,  a Swede,  and  professor  at  Upsal, 
in  1652. 

In  1668,  M.  Louis  de  Bills  appears  to  have  traced  lymphatic  vessels 
from  the  ‘jugular  glanduls’  of  a dog  to  the  thoracic  duct.  See  Phil. 
Trans.,  iii.  (1668),  p.  791. 

But  the  lympliatic  absorbents  had  never  been  distinguished  as  a system, 
either  anatomically  or  physiologically,  from  the  capillary  vessels. 

Noquez,  who  of  all  anatomists  before  the  Hunters,  had  dwelt  more  par- 
ticularly on  the  lymphatics,  and  who  was  cited  by  some  of  the  contem- 
poraries of  the  Hunters  as  having  anticipated  them  in  this  department  of 
their  anatomical  labours,  divided  the  lymphatics  into  four  classes:  one  of 
these  corresponded  with  the  capillary  blood-vessels  of  modern  physiolo- 
gists ; a second,  witli  the  serous  exhalant  arteries  ; a third,  to  the  veins 
corresponding  with  these  arteries,  and  to  which  Noquez  gave  the  name 
of  ‘ conduits  absorbents,’  until  they  became  large  enough  to  be  sensible 
to  the  naked  eye,  and  began  to  receive  red  blood.  His  fourth  class  of 
lymphatics  includes  the  absorbent  vessels  of  the.  Hunters,  and  were 
described  by  Noquez  as  ending  in  the  receptaculum  chyli,  the  thoracic 
duct,  the  vena  cava,  and  the  vena  portarum. 

It  is  therefore  obvious  that  the  Hunterian  doctrine  of  the  absorbent  sys- 
tem was  in  no  way  anticipated  by  Noquez,  who  appears  to  have  been  a 
mere  compiler,  undistinguished  by  any  original  research,  and  whose 
anatomical  treatise  was  professedly  an  improvement  upon  Keill’s. 

With  respect  to  the  extension  of  our  knowledge  of  the  condition  of  the 
lymphatic  system  in  the  human  subject,  it  appears  that  Mr.  Hunter  greatly 
contributed  to  this  important  branch  of  anatomy.  Dr.  Hunter  describes 
one  of  his  preparations,  which  showed  the  lymphatic  vessels  extending 
from  the  ham  upwards  to  the  thoracic  duct,  as  well  as  the  inguinal  and 
lumbar  glands,  and  the  larger  lacteals  at  the  root  of  the  mesentery,  the 
receptaculum  chyli,  or  what  is  so  called,  all  finely  filled  with  mercurj'". 
He  acknowledges  his  brother’s  discovery  in  1753  or  1754,  that  the  lym- 
phatic glands,  and  the  lymphatic  vessels  going  from  them,  could  be  filled 
uniformly  by  pushing  a pipe  into  their  substance  : and  states  it  to  have  been 
Mr.  Hunter’s  intention  to  have  traced  the  lymphatic  vessels  all  over  the 
body,  and  to  have  given  a complete  description  and  figure  of  the  whole 
absorbing  system.  This  work  was  unfortunately  arrested  by  a very 
indifferent  state  of  health,  the  effect  of  too  much  application  to  anatomy, 
which  obliged  Mr.  Hunter  to  be  much  in  the  country.  It  was  afterwards, 
as  is  well  known,  ably  accomplished  by  another  ornament  of  the  Hun- 
terian school,  the  celebrated  Cruikshank. 

When  the  question  of  the  office  of  the  lymphatics  first  began  to  be 
agitated,  one  of  the  arguments  against  their  being  the  exclusive  agents  of 
the  absorbing  processes  was  founded  on  their  supposed  absence  in  the 
oviparous  vertebrala.*  The  discovery  of  this  system  of  vessels  in  birds 

* [“  Lacteal  vessels  have  not  as  yet  been  certainly  observed  in  birds,  or  in  the  more 
common  fishes,  nor  in  general  in  the  animals  called  oviparous  ; and,  from  a considerable 
number  of  experiments  I have  made,  I am  convinced  they  want  the  lymphatics  as  well 
as  the  lacteal  vessels.”  Monro,  Observations  Anatomical  and  Physiological,  8vo. 
Edinb.,p.  57,  1758. 


OF  ABSORPTION  B5T  VEINS. 


313 


formed,  therefore,  no  unimportant  support  to  the  views  of  Dr.  William 
Hunter,  and  to  this  discovery  Mr.  Hunter  is  justly  entitled.  Mr.  Hewson, 
who  first  published  on  the  lymphatics  of  birds,  and  who  discovered  their 
lacteal  absorbents,  acknowledges  that  “ it  is  but  doing  justice  to  the  inge- 
nious Mr.  John  Hunter  to  mention  here  that  these  lymphatics  in  the  necks 
of  fowls  were  first  discovered  by  him  many  years  ago.”  (Phil.  'Frans., 
1788,  p.  220.)  And  it  appears  from  Dr.  Monro’s  reply  to  Mr.  Hewson, 
that  this  discovery  of  Mr.  Hunter’s  had  been  communicated  to  Dr.  Cullen 
by  Dr.  George  Fordyce,  and  had  materially  influenced  Dr.  Monro’s 
opinions  respecting  the  absorbent  system. 

Mr.  Hewson  also  informs  us,  that  prior  to  his  own  puitlication  on  the 
Absorbent  System  of  Amphibia,  Mr.  Hunter  had  discovered  and  demon- 
strated to  him  the  chyle,  and  we  must  suppose  the  lacteal  vessels,  of  a 
crocodile. 

With  respect  to  the  absorbent  system  in  fish,  the  discovery  of  this  must 
be  awarded  to  Mr.  tiewson. 

As  early  as  1701  experiments  had  been  instituted  with  a view  to  dis- 
cover the  function  of  the  lacteal  vessels,  indicated  of  old  by  Erasistratus, 
and  rediscovered  by  Asellius.  Martin  Lister  and  Musgrave  satisfied  them- 
selves that  coloured  matter  was  taken  up  by  these  vessels  which  they 
termed  lacteal  veins,  from  the  intestine.*  Nevertheless,  until  the  obser- 
vations and  experiments  of  the  Hunters,  the  lymphatics  generally  were 
believed  by  Haller  and  other  physiologists  to  be  simply  continuations  of 
capillary  or  lymphatic  arteries,  and  they  were  supposed  to  have  no  other 
function  than  to  carryback  into  the  circulation  the  serum  or  lymph  of  the 
blood.  Dr.  William  Hunter  having  observed  that  he  could  not  inject  the 
lymphatics  from  the  arteries  excepting  the  injection  were  extravasated  in 
the  cellular  substance,  but  that  he  could  readily  inject  the  lymphatics 
both  from  the  common  cellular  substance  and  that  which  assists  in  form- 
ing the  parenchyma  of  the  glands,  as  the  testis,  spleen,  &c. ; observing 
also  that  the  course  of  the  venereal  poison,  when  introduced  into  the 
system,  indicated  that  it  was  carried  along  by  the  lymphatics,  affecting 
the  inguinal  glands  when  applied  to  the  glans  penis  or  prepuce,  and  in 
like  manner  affecting  the  glands  of  the  armpits  when  applied  to  the  hands, 
and  the  cervical  glands  when  communicated  by  the  lips ; perceiving  also 
the  close  analogy  of  the  lymphatics  to  the  lacteal  absorbents,  in  their 
valvular  structure  and  mode  of  termination  ; he  concluded  from  all  these 
circumstances  that  they  had  an  analogous  function  ; that  they  were  not 
reflected  capillary  arteries,  but  originated  from  all  tlie  interstices  and  cavi- 
ties of  the  body,  forming  the  absorbing  vessels  of  the  general  system,  as 
the  lacteals  were  allowed  to  be  of  the  alimentary  canal. 

'Fhis  doctrine  was  supported  by  the  experiments  of  John  Hunter  given 
in  the  text,  which  were  first  published  in  1762,  while  he  was  abroad  with 
the  army  at  Belleisle,  by  his  brother.  Dr.  William  Hunter,  in  the  Medical 
Commentaries.  It  would  seem,  however,  that  Mr.  Hunter  did  not  consider 
these  alone  as  sufficiently  conclusive  to  be  submitted  to  the  public,  since 
he  left  them  in  manuscript  with  his  brother,  who  made  use  of  them,  four 
years  afterwards,  in  the  controversial  essay  with  the  Monros,  while  John 

* [See  Experi.Tients  for  transmitting  Blue-coloured  Liquor  into  the  Lacteals.  Mus- 
grave, Phil.  'Trans.,  vol.  xii.  p.  996.  Experiments  for  altering  the  Colour  of  the  Chyle 
in  the  Lacteal  Veins,  by  M.  Lister,  Phil.  Trans.,  vol.  xiii.,  p.  6.  Powdered  Blues  pass 
into  Lacteal  Veins,  ibid.,  vol.  xxii.,  p.  819.] 

28 


314 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


was  abroad  with  the  army  at  Belleisle.  They  were  iinaecompanied  by 
any  additional  proof  or  observations,  but  were  considered  by  Dr.  William 
Hunter  as  being  decisive  in  depriving  the  veins  of  the  power  of  absorb- 
ing altogether.  Mr.  Hunter,  however,  continued  these  experiments  in 
other  classes,  as  is  shown  in  the  following  manuscript  note  in  the  posses- 
sion of  Mr.  Clift.  “ The  experiments  upon  the  bird,  to  ascertain  whether 
the  mesenteric  veins  absorbed  or  not,  were  nearly  the  same  with  those 
made  upon  the  ass,  in  1758,  with  musk,  as  also  with  spirits  of  wine ; and 
although  in  those  researches  I did  not  discover  the  lacteals  in  the  bird, 
yet  I discovered  that  the  red  veins  in  the  mesentery  in  them  most  proba- 
bly did  not  absorb,  because  I never  could  find  any  of  the  liquors  which  had 
been  thrown  into  the  gut  mixed  with  the  blood  of  the  veins  of  the  mesentery  ; 
and  which  I look  upon  as  one  of  the  first  steps  towards  proving  another 
system.”  Subsequent  experiments,  especially  those  of  Tiedemann  and 
Gmelin,  Meyer  and  Segalos,  have  shown  that  a povver  of  absorption  can- 
not be  denied  to  the  veins  ; yet  the  admission  of  this  power,  (which  must 
be  granted  on  anatomical  grounds  to  the  veins  of  all  invertebrate  animals, 
and  to  some  parts,  probably,  of  the  vertebrate,  as  the  eye  and  the  brain,) 
does  not  invalidate  or  diminish  the  credit  due  to  those  experiments  and 
enlarged  conceptions  of  the  uses  and  anatomical  relations  oftlie  lymphatics, 
by  which  the  true  function  of  these  vessels  was  ascertained.  1 say  the 
true  function  ; for  though  it  be  admitted  that  the  veins  absorb,  yet  every 
physiologist,* — with  the  exception  of  one  who  has  held  the  sympathetic 
nerve  to  be  no  nerve,  and  who,  in  the  nineteenth  century,  denied  that  rep- 
tiles and  fishes  had  lymphatic  vessels, — allows  that  absorption,  and  the 
effecting  a certain  change  in  the  nature  of  the  absorbed  liquors  are  the 
only  functions  which  the  lymphatic  vessels  perform. 

I would  here  for  the  present  willingly  leave  the  subject,  but  that  I feel 
it  incumbent  upon  me,  in  regard  to  the  character  of  an  author  whose  works 
have  exercised  so  great  and  salutary  an  influence  over  the  surgical  profes- 
sion, to  show  tliat  the  charge  of  imperfection  and  negligence*  which  has 
been  cast  upon  the  Hunterian  experiments, — whose  want  of  exactness, 
according  to  M.  Majendie,  can  only  be  excused  by  the  rude  state  in  which 
the  art  of  physiological  experiment  was  at  the  period  when  they  were 
made, — rests  entirely  on  the  culpable  oversight  of  the  accuser. 

In  relating  one  of  his  experiments,  Mr.  Hunter  states  : “ Nov,  13,  1758, 
I opened  the  abdomen  of  a living  sheep,  which  had  eaten  nothing  for 
some  days  ; and  upon  exposing  the  intestines  and  mesentery  we  ob- 
served the  lacteals  were  visible,  but  contained  only  a transparent  watery 
fluid.” 

Is  it  conceivable  that  any  succeeding  physiologist  would  have  ventured, 
in  his  commentary  on  Mr.  Hunter’s  experiments,  to  object  to  them,  “ be- 

* [“  L’etat  (I’imperfection  on  ^tait  I’art  des  experiences  physiologiques  a I’epoque  ou 
J.  Hunter  a fait  celle-ci  peut  seui  excuscr  ce  celebre  anatomiste  de  n’avoir  pas  senti 
combien  il  y manque  de  circonstances  importantes  pour  que  Tun  puisse,  en  la  suppo- 
santexacte,  en  tirer  quelques  consequences.  En  effet,  pour  que  cette  experience 
piit  etre  de  quelque  utilite  il  faudrait  savoir  si  I’aniraal  etaitajeun  lorsqu’on  I’a 
ouvert,  ou  s’il  etait  dans  le  travail  de  la  digestion  ; il  aurait  fallut  examiner  I’etat  des 
lymphatiques  au  commencement  de  I'experience  ; etaient-ils  ou  n’etaient-ils  pas  pleins 
de  chyle,”  &c.  And  again,  “ Hunter  fait  une  fausse  theorie  sur  I’une  de  fonctions  les 
plus  importantes  de  la  vie,  il  I’etaie  a peine  de  quelques  experiences  inexactes,  et  dans 
tous  les  cas  insuffisantes.” — Precis  Elementaire  de  Physiologie,  (3me  ed.)  tom.  ii. 
pp.  199,  201.] 


OF  ABSORPTION  BY  VEINS. 


315 


cause  the  experimenter  had  neglected  to  notice  whether  the  animal  experi- 
mented on  was  full  or  fasting  ; or  whether  the  lacteals  were  or  were  not 
distended  with  chyle  ?” 

To  give  a colour  to  this  objection,  all  reference  to  the  experiment  above 
quoted  is  avoided  in  the  ‘ Precis  Elementaire but  even  in  the  very  ex- 
periment of  which  M.  Majendie  gives  a mutilated  version,  Mr.  Hunter 
expressly  premises  that,  “ having  exposed  the  intestines  fully,  he  observed 
the  lacteals  filled  with  a white  liquor  at  the  upper  part  of  the  gut  and  me- 
sentery ; but  in  those  that  came  from  the  ileon  and  colon  the  liquor  was 
transparent.” 

In  the  herbivorous  quadruped,  the  sheep,  in  which  Mr.  Hunter  employed 
starch  as  the  menstruum  of  the  indigo,  the  transparent  watery  nature  of 
the  contents  of  the  lacteals  was  especially  noted  before  the  colouring  ma- 
terial was  thrown  into  the  intestines:  they  were  afterwards  observed  to  be 
filled  with  a fluid  of  a fine  blue  colour.  And  yet  M.  Majendie  (ibid., 
p.  210)  would  have  us  believe  that  no  alteration  had  been  observed ; that  the 
lacteals  were  of  the  same  blue  colour  before  the  injection  of  the  indigo 
and  starch  had  been  performed  as  after. 

Whether,  however,  the  coloured  matter  had  passed  into  the  lacteals  or 
not,  it  could  not,  by  the  most  careful  and  varied  experiments,  be  detected 
in  the  veins.  Great  precaution  was  taken  to  ascertain  that  fact.  Since 
the  natural  colour  of  the  blood  rendered  it  difficult  to  perceive  a change 
of  hue,  the  contents  of  the  veins  were  collected  and  suffered  to  coagulate, 
in  the  expectation  of  the  serum  manifesting  the  presence  of  the  indigo; 
but  it  had  not  the  least  bluish  tint. 

Warm  milk  was  then  made  to  circulate  from  the  artery  into  the  vein  ; 
and  it  might  surely  have  been  expected,  especially  if  the  doctrine  of  non- 
vital  imbibition  advocated  by  M.  Majendie  were  true,  to  have  then  had  a 
trace  of  the  coloured  contents  of  the  intestine  in  the  venal  milk;  but  no 
such  result  took  place. 

The  experiment  upon  the  ass,  in  which  the  odour  of  musk  was  pre- 
sent in  the  chyle,  but  not  in  the  venous  blood,  is  not  referred  to  by  AI. 
Majendie. 

In  making  these  comments  it  is  by  no  means  intended  to  uphold  the 
infallibility  of  Mr.  Hunter ; but  it  nvay  be  safely  averred  that  a candid 
and  careful  perusal  of  his  experiments  on  absorption,  recorded  in  the  text, 
will  not  only  exonerate  him  from  any  charge  of  haste  or  negligence,  but 
must  impress  the  unprejudiced  reader  with  the  conviction  that  those  expe- 
periments  have  rarely  been  equalled  and  never  excelled,  either  in  the  in- 
genuity and  foresight  manifested  in  their  contrivance,  in  the  skill  and  pre- 
caution against  error  displayed  during  their  performance,  in  the  fairness 
of  the  conclusions  deduced  from  them,  or  in  the  minute  accuracy  and 
candour  which  pervade  their  narration. 

To  prove  the  absorbent  power  of  the  lymphatics,  however,  is  one 
thing ; that  the  veins  are  thereby  deprived  of  the  power  of  absorbing 
altogether  is  another ; and  it  is  in  reference  to  tiiis  latter  question  that  the 
experiments  of  M.  Flandrin,  recorded  by  M.  Majendie,  become  interesting 
to  the  physiologist.  But  we  may  observe,  en passant,  that  if  M.  Majendie 
and  his  collaborateur  failed  to  obtain  the  same  results  as  Hunter  from 
similar  experiments,  other  and  as  able  experimenters  in  recent  times  have 
been  more  successful.  Schroeder  von  der  Kolk,  for  example,  filled  a 
loop  of  intestine  in  a living  dog  with  a solution  of  the  ferro-prussiate  of 


316 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


potass,  and  included  the  distended  loop  between  two  ligatures.  He  then 
placed  the  loop  and  its  contents  in  a solution  of  sulphate  of  iron.  'I'he 
blue  compound,  which  could  be  formed  by  no  other  meilns  except  by  the 
union  of  the  two  chemical  fluids,  was  manifested  in  the  lacteals  alone,  and 
not  in  the  veins.  {Muller's  Physiologie,  p.  '2,29.)  Viridet  and  Mattel 
also  found  that  the  chyle  derived  from  yolk  of  egg  was  yellow,  while  that 
from  food  mixed  with  madder  was  red. 

It  is  allowed  indeed  by  all  physiologists,  and  even  by  M.  Majendie, 
that  the  lacteals  absorb  the  chyle.  But  various  experiments  seem  to  show 
that  other  fluids,  and  especially  those  of  a poisonous  nature,  are  taken  up 
from  the  intestines  by  the  veins.  Such  was  the  general  result  of  the 
numerous  experiments  of  Tiedemann  and  Gmelin.*  Those  related  by 
Majendie  are  not,  however,  free  from  objection.  He  opened  the  abdomen 
of  a dog ; a loop  of  intestine  was  included  between  two  ligatures  and 
separated  from  the  rest  of  the  canal,  all  other  connection  between 
the  intestine  and  the  rest  of  the  body  was  destroyed  except  a single 
mesenteric  artery  and  vein.  Two  ounces  of  the  decoction  of  nux 
vomica  were  then  injected  into  the  detached  portion  of  gut.  In  six 
minutes  the  effects  of  the  poison  manifested  themselves  with  the  ordinary 
intensity.  Great  precaution  was  taken  to  obviate  the  doubt  which  any 
lacteals  remaining  attached  to  tlie  coats  of  the  vessel  might  have  occasioned ; 
but  as  this  objection  might  still  be  urged,  the  following  more  conclusive 
experiment  was  performed  : a limb  of  a dog  was  amputated  with  the  ex- 
ception of  a single  artery  and  vein,  which  alone  kept  up  the  communica- 
tion between  the  limb  and  the  trunk ; upas  poison  was  then  inserted  into 
the  foot  {enfonces  duns  luyatte).  Its  effects  became  evident  in  less  than 
four  minutes  ; in  less  than  ten  the  animal  was  dead.  To  avoid  the  objec- 
tion of  invisible  lymphatics  in  the  tissue  of  the  vessels,  a segment  of  both 
artery  and  vein  was  removed,  after  having  substituted  a portion  of  quill, 
so  that  there  remained  no  other  communication  between  the  limb  and  the 
animal  excepting  by  the  blood  which  circulated  from  one  to  the  other. 
The  poison  introduced  into  the  foot  {introduit  dansla  yatte)  produced  its 
efl’ects  in  about  four  minutes.  What  makes  it  so  evident,  adds  M. 
Majendie,  that  the  crural  vein  was  the  sole  medium  of  introduction  to  the 
poison  is  this  ; that  simple  compression  of  this  vessel  arrested  the  deadly 
effects  of  the  upas,  which  again  immediately  manifested  themselves  on  a 
remission  of  the  pressure.* 

Now,  although  the  objection  of  lymphatics  in  the  coats  of  the  vessels  is 
obviated  in  this  experiment,  yet  its  conclusiveness  may  be  questioned  on 
this  ground,  that  the  poison  is  applied  to  a wound  where  it  can  enter  the 
circulating  fluids  by  open  and  divided  veins  ; but  this  is  by  no  means  the 
condition  which  is  understood  in  the  theory  of  venous  absorption,  which 
relates  only  to  an  action  attributed  to  the  veins  in  their  natural  state,  and 
through  the  medium  of  their  organic  pores.  If  this  objection  be  invalidated 
by  the  experiment  in  which  the  decoction  of  nux  vomica  was  applied  to 
an  entire  mucous  surface,  as  when  injected  into  the  intestine,  yet  this  may 
be  accounted  for  by  the  paralyzing  effects  of  the  narcotic  upon  the  animal 
tissues  with  which  it  comes  in  contact : it  may  be  objected  that  their 
vitality  is  destroyed,  that  inorganic  imbibition  then  takes  place,  and  that 

* [Versuche  liber  die  Wege  auf  welcliem  Substanzen  aus  dem  Magen  und  Harm 
Kanal  ins  Blut  gelangen.] 

j-  [Loc.  cit.,  p.  255,  256.] 


OF  ABSORPTION  BY  VEINS. 


317 


the  poison  thus  passes  into  the  cavity  of  the  vessels,  and  is  carried  along 
the  returning  currents  to  the  heart. 

But  objections  from  the  permeability  of  the  tissue  of  a paralyzed  vein 
are  endeavoured  to  be  overcome  by  the  assertion  tliat  all  absorption  is  the 
efl'ect  of  non-vital  imbibition,  that  it  is  a property  which  the  living  animal 
tissues  possess  in  common  with  inorganic  substances. 

Thus  M.  Fodera  having  repeated  the  experiment  of  M.  Majendie  and 
Segalas,  in  which  the  solution  of  nux  vomica  was  injected  into  the  intes- 
tine, afterwards  incloses  the  same  poisonous  solution  in  a dead  portion  of 
intestine,  inserts  this  into  a loop  of  the  intestines  of  a living  animal,  and 
from  the  effect  produced  by  the  transudation  of  the  poison  through  the 
parietes  of  the  dead  intestine,  and  through  the  paralyzed  surface  of  that 
of  the  animal  experimented  upon,  draws  a sweeping  conclusion  as  to  the 
nature  of  absorption  in  general. 

M.  Majendie  also  rejects  the  theory  of  the  vital  actions  of  the  absorbents, 
and  strongly  condemns  the  supposition  of  a selecting  power  in  absorbent 
pores  as  gratuitous  and  unphilosophical.  He  threw  into  the  thorax  of  a 
dog  a solution  of  nux  vomica,  and  he  found  that  in  proportion  as  the  ob- 
stacles to  a free  circulation  were  increased,  by  distending  the  blood-vessels 
with  warm  water,-  the  effects  of  the  poison  on  the  system  were  retarded. 
This  experiment  is  of  the  same  species  as  that  by  M.  Segalas,  who  limit- 
ed the  field  of  observation  by  confining  the  poison  within  a loop  of  intes- 
tine, and  interrupted  the  venous  current  altogether  by  a ligature  ; it  is 
consequently  less  eonclusive,  though  liable  to  the  same  objections.  When 
M.  Majendie  removed  the  obstacles  which  he  had  imposed  on  the  circula- 
tion by  opening  a vein  and  relieving  the  distended  vessels,  the  imbibed 
solution  of  nux  vomica  rapidly  produced  its  effects.  Thus  the  ordinary 
laws  of  the  living  tissue  being  suspended  by  the  application  of  a narcotie 
or  other  poison  to  them,  and  mechanical  imbibition  being  thereby  per- 
mitted,— or  when  similar  poisons  are  directly  applied  to  divided  vessels; 
— it  may  be  concluded,  from  the  experiments  above  quoted,  that  whatever 
arrests  the  return  of  the  empoisoned  blood  to  the  heart,  whether  atmo- 
spheric pressure,  produced  by  the  action  of  an  exhausted  cupping-glass, 
or  by  the  direct  pressure  or  ligature  of  the  vein,  or  a general  impediment 
to  the  circulation  by  a plethoric  or  artificial  distension  of  vessels,  will 
proportionately  retard  the  deadly  operations  of  the  poison.  M.  Majendie 
has  also  shown  that  the  rapidity  of  its  action  is  increased  by  artificially 
diminishing  the  quantity  of  circulating  fluids,  and  this  observation  is  of 
great  value  in  a practical  point  of  view;  but  much  is  still  wanting  to  sus- 
tain his  conclusion  that  the  ordinary  and  natural  absorbent  processes  are 
arrested  by  a plethoric  or  distended  state  of  the  vessels,  and  vice  versa. 

The  experiments  by  which  M.  Majendie  endeavours  to  support  the 
theory  of  non-vital  imbibition  or  capillary  attraction  as  the  immediate 
cause  of  absorption  are  these  : — A saturated  solution  of  nux  vomica 
applied  to  the  denuded  vein  of  a living  animal  passes  through  the  coats 
of  that  vein  into  the  circulation  and  kills.  The  poison  takes  a longer 
time  to  soak  through  the  coats  of  an  artery  ; but  having  done  so  produces 
the  same  deadly  effect.  (Zoc.  cit.,  pp.  279,  280.)  The  nux  vomica  had 
certainly  affected  the  system  by  transuding  through  the  coats  of  the  vessels, 
for  its  bitter  taste  could  be  detected  in  the  blood  which  adhered  to  the 
inside  of  the  coat  of  the  paralysed  vessels.  Dead  vessels  and  animal 
membranes  exhibited  the  same  permeability  as  those  which  M.  Majendie 

28*= 


318 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


imagines  to  have  retained  their  vital  properties  unchanged  after  four  or 
ten  minutes’  contact  with  the  narcotic  extract.  Ink.  injected  into  the 
serous  cavities  of  the  body  of  a living  animal  stains  the  lining  membrane 
and  contiguous  parts,  (p.  282.) 

From  these  experiments  tlie  author  concludes,  “II  me  parait  done 
hors  de  doute  que  tons  les  vaisseaux  sanguins,  arteriels  et  veinetix,  morts 
ou  vivans,  gros  ou  petits,  presentent,  dans  leurs  parois,  une  propriete 
physique  propre  ii  rendre  parfaitement  raison  des  principaux  phenomenes 
de  I’absorption.” — Ibid. 

'I'o  be  consistent  in  this  application  of  the  theory  of  physical  imbibition 
to  the  actions  of  organized  bodies,  we  ought  to  conclude,  from  observing 
the  serum  transuded  after  death  into  the  ]>ericardium,  that  such  was  the 
condition  in  the  living  state  of  the  parts  ; and  a physiologist  could  no 
longer  infer  from  the  diflerent  appearance  of  the  parts  in  the  immediate 
proximity  of  the  gall-bladder,  when  examined  in  a living  and  dead  animal, 
that  the  condition  of  tlie  coats  of  that  receptacle  as  to  permeability  must 
be  influenced  by  the  two  states  ; and  that  the  living  tissue  resists  the 
percolation  which  the  dead  membrane  readily  allows.  M.  Majendie  is, 
in  fact,  compelled  by  his  theory  to  deny  such  difference;  “ the  bile,” 
says  he,  “ does  transude  through  the  coats  of  the  living  gall-bladder,  but 
the  sanguineous  current  which  exists  in  the  small  vessels  which  form  in 
great  measure  those  parietes,  carries  it  off  in  proportion  as  it  transudes.” 
Yet  the  same  currents  in  the  serous  membranes,  which  at  p.  258  he  admits 
are  more  abundant  in  vessels  than  the  mucous,  have  no  such  effect  in 
preventing  the  passage  of  the  ink,  &c. 

But  it  is  evident  that  he  is  liimself  not  satisfied  with  his  explanation, 
for  in  an  account  of  one  of  the  Hunterian  experiments,  in  which  means 
rvere  adopted  to  ascertain  whether  water  injected  into  the  intestine  of  a 
living  animal  would  be  absorbed  by  the  vein,  M.  Majendie  observes  that 
the  vital  action  of  the  vein  might  be  interrupted  by  the  ligature  of  its  cor- 
responding artery.  Now  this  objection  ought  to  have  no  weight  if,  as 
he  supposes,  the  veins  absorb  by  a property  of  simple  inorganic  imbibition 
with  which  their  coals  are  endowed.  But  laying  aside  for  a moment  the 
consideration  of  experiments,  in  all  of  which  the  vital  operations  are  more 
or  less  interrupted,  and  the  parts  in  question  forced  into  unnatural  condi- 
tions, let  us  attentively  consider  those  phajnomena  of  absorption  which 
Nature  plainly  puts  before  our  eyes.  The  chyle  is  known  to  contain 
globules  of  a definite  size  and  form.  It  is  admitted  by  M.  Majendie  that 
this  fluid  is  exclusively  taken  up  by  the  lacteal  absorbents.  The  escape 
of  the  lacteal  globules  from  the  intestine  could  not  be  accounted  for  on  the 
theory  of  imbibition  or  permeability  of  tissue;  organic  pores  must  be 
supposed  to  exist  of  a size  adequate  to  their  transmission.  These  pores 
have  been  described  by  Cruikshank  as  they  were  seen  by  himself  and 
Dr.  Win.  Hunter  in  the  human  subject;  they  have  been  witnessed  by 
Majendie  in  a dog.  But,  says  Majendie,  it  is  unphilosophical,  a mere 
physiological  romance,  to  suppose  that  they  can  act  in  any  way  different 
from  dead  animal  tissues  ; physical  imbibition,  inorganic  capillary  attrac- 
tion is  the  only  cause  of  the  transmission  of  fluids  through  animal  mem- 
branes that  we  are  acquainted  with,  &c.  Yet  these  organized  pores  of 
the  lacteal  absorbents  permit  nothing  to  pass  them,  according  to  his  own 
admission,  except  the  chyle. 

Still  it  is  contended  that  this  must  be  a mechanical  action,  because 
lacteal  absorption  has  been  observed  to  go  on  in  a dog  for  two  hours  after 


ON  THE  GROWTH  OF  BONES. 


319 


death  ; but  what  does  this  prove  but  that  the  automatic  or  involuntary 
actions  continue  for  a certain  time  after  the  sensorial  power  is  lost, — 
after  apparent  death  has  ensued  ? 

Tints  the  only  natural  absorbent  process  in  the  living  body  that  we  can 
reason  upon  from  the  evidence  afforded  by  the  nature  of  the  substance 
absorbed,  and  the  ascertained  structure  of  the  mechanism  employed  in  its 
absorption,  is  totally  at  variance  with  the  theory  of  non-vital  imbibition 
as  the  cause  of  absorption,  and  can  only  be  explained  by  a vital  or  organic 
endowment  of  the  parts  concerned,  whether  it  be  regarded  as  a power  of 
selection  or  mutual  attraction,  or  an  action  whose  peculiar  stimulus  is  the 
contact  of  chyle. 

The  various  phenomena  of  excretory  absorption,  as  it  may  be  termed, 
render  the  theory  of  the  capillary  attraction  of  the  tissue,  whether  of  veins 
or  lymphatics,  as  their  cause,  equally  unsatisfactory.  A property  of  dead 
matter  cannot  account  for  the  rapid  absorption  of  fat  in  disease  ; or  of  the 
parts  of  muscles,  &c.,  which,  from  some  accident  to  a joint,  have  become 
useless  ; or  of  alveoli  of  shed  teeth  ; or  of  the  parts  which  in  the  progress 
of  growth  become  inconveniently  situated,  as  the  first  deposit  of  osseous 
matter  in  long  bones  ; or  of  parts  which,  at  the  conclusion  of  growth,  are 
equally  inconveniently  situated  in  regard  to  some  tumour  or  collection  of 
matter,  the  discharge  of  which  is  salutary  to  the  constitution,  &c.  A 
mere  physical  endowment  of  animal  tissues  ought  always  to  be  acting, 
and  acting  in  but  one  way  ; and  we  therefore  conclude,  with  Hunter,  that 
these  various  and  partial  operations  of  the  lymphatics  are  affected  by  the 
vital  actions  of  organic  pores,  in  a manner  analogous  to  that  which  de- 
termines in  the  lacleals  the  exclusive  absorption  of  chyle. jj 


31.  EXPERIMENTS  AND  OBSERVATIONS  ON  THE 
GROWTH  OF  BONES,  FROM  THE  PAPERS  OF  THE 
LATE  MR.  HUNTER. 

[Published  by  Mr.  (afterwards  Sir  Everard)  Home,  in  the  Second  Volume  of  the  Trans- 
actions of  a Society  for  the  Improvement  of  Medical  and  Chirurgical  Knowledge.] 

Read  October  4,  1798. 

Mr.  Hunter’s  Observations  on  the  Growth  of  Bones  have  been 
mentioned  in  his  lectures  ever  since  the  year  1772,  the  first  year  in 
which  he  gave  lectures,  and  have  been  since  adopted  by  the  prin- 
cipal teachers  of  anatomy  in  London  ; it  was  therefore  natural  for 
rne  to  suppose  that  they  were  generally  known.  In  this,  however, 
I find  I have  been  mistaken,  since  the  present  Professor  of  Anatomy 
in  Edinburgh,  in  a late  publication,  declares  himself  an  advocate  for 
the  doctrine  of  Du  Hamel ; and  from  what  he  advances,  it  appears 
that  he  was  not  at  all  acquainted  with  Mr.  Hunter’s  experiments 
upon  this  subject. 

Under  thesecircumstanc.es  I lay  before  the  Society  Mr.  Hunter’s 
experiments  and  observations,  that  they  may  be  made  known  to  the 
public.* 

* [This  record  contains  little  more  than  a brief  notice  of  the  general  results  of 
Mr.  Hunter’s  Observations  and  Experiments  on  the  Growth  of  Bone.] 


320 


HUNTER  ON  THE  ANIMAL  GEUONOMY. 


It  was  some  time  anterior  to  the  year  1772  that  Mr.  Hunter 
began  to  investigate  this  subject,  and  an  account  of  the  experiments 
and  observations  was  given  to  me  to  copy  in  that  year,  as  a part 
of  his  future  lectures. 

Du  Hamel  had  published  a very  ingenious  theory  upon  the  growth 
of  bones,  which  he  endeavoured  to  support  by  experiments  tending 
to  prove  that  bones  grow  by  the  extension  of  their  parts.  With 
this  doctrine  Mr.  Hunter  was  not  satisfied,  and  instituted  experiments 
to  determine  the  truth  of  Du  Hamel’s  opinion. 

Mr.  Hunter  began  his  experiments  by  feeding  animals  with  mad- 
der, which  has  a property  of  tinging  with  a red  colour  that  part 
only  of  the  bone  which  is  added  while  the  animal  is  confined  to  this 
particular  food.* 

He  fed  two  pigs  with  madder  for  a fortnight,  and  at  the  end  of 
that  period  one  of  them  was  killed  ; the  bones,  upon  examination  ex- 
ternally, had  a red  appearance;  when  sections  were  made  of  them, 
the  exterior  part  was  found  to  be  principally  coloured,  and  the  in- 
terior was  much  less  tinged. 

* [This  effect  of  madder  upon  bone  (first  described  in  England  by  Belchier, 
Phil,  Tr.,  vol.  xxxix.,  1736,  p.  287),  depends  on  the  following  chemical  properties. 
The  colouring  principle  of  y\\e  Ituhia  Tinctorum  has  a strong  affinity  to  phosphate 
of  lime,  which  earth,  if  artificially  precipitated  from  a solution  of  madder,  carries 
down  with  it  the  colouring  matter  in  a state  of  combination,  which  water  does 
not  disturb. 

The  colouring  principle  of  madder  is  hardly  soluble  in  water,  but  is  readily  and 
abundantly  soluble  in  albuminous  fluids,  and,  consequently,  when  taken  into  the 
system  as  food,  it  is  carried  along,  dissolved  in  the  serum  of  the  circulating  blood, 
and  is  deposited,  combined  with  the  phosphate  of  lime,  wherever  that  salt  is 
separated  from  the  blood  to  contribute  to  the  increase  or  reparation  of  bone. 

'J'bere  are  still,  however,  some  points  connected  with  this  subject  to  be  deter- 
mined before  the  reasoning  from  experiments  with  madder  on  the  growth  of  bone 
can  have  all  the  desirable  exactness.  Whether,  e.  g.  the  colouring  principle  of 
madder,  after  having  been  precipitated  from  the  blood  in  combination  with  the 
phosphate  of  lime,  remains  in  the  bone  until  the  particles  of  the  earth  are  them- 
selves removed, — or  whether  the  colouring  matter  may  again  be  redissolved  in 
the  serum  of  the  blood  circulating  through  the  substance  of  the  bone, — are  ques- 
tions not  yet  definitively  settled  ; but  there  is  much  reason  for  believing  that  the 
colouring  matter  may  be  removed  without  the  earth  with  which  it  had  been  com- 
bined. Accordingly,  although  an  inference  may  be  safely  drawn  with  respect  to 
the  part  of  a growing  bone  which  receives  the  accessions  of  osseous  substance, 
by  observing  the  part  which  is  coloured  with  madder,  yet  we  cannot  so  certainly 
conclude  that  a superficial  colourless  layer,  in  an  animal  killed  after  remission  of 
the  madder,  is  a new  deposit,  since  it  may  be  the  old,  from  which  the  madder  has 
been  removed,  after  having  been  redissolved  in  the  serum. 

That  the  madder  “ tinges  with  a red  colour  that  part  only  of  the  bone  which  is 
added,”  as  is  stated  in  the  text,  is  an  assertion,  not  only  unsupported  by  any  physio- 
logical reasoning,  but  directly  in  contradiction  to  Hunter’s  own  statement,  “that 
any  part  of  a bone  which  is  already  formed  is  capable  of  being  dyed  with  madder, 
though  not  so  fast  as  the  part  that  is  forming.” 

I may  observe,  incidentally,  that  the  phaenomena  under  consideration  throw 
light  upon  the  chemical  condition  under  which  phosphate  of  lime  is  contained  in 
the  living  body.  Since  the  colouring  principle  of  madder  has  no  affinity  for  lime 
or  calcium  alone,  it  is  clear  that  the  phosphate  of  lime  is  not  contained  in  the 
blood  or  the  bones  as  phosphorus,  o.xygen,  and  calcium,  but  that  it  exists  as  a 
binary  compound,  and  is  mixed  as  phosphate  of  lime  with  the  cartilage  or  animal 
basis  of  the  bones.] 


ON  THE  GROWTH  OF  BONES. 


321 


The  other  pig  was  allowed  to  live  a fortnight  longer,  but  had  now 
no  madder  in  its  food  ; it  was  then  hilled,  and  the  exterior  part  of 
the  bones  was  found  of  the  natural  colour,  but  the  interior  was  red. 

He  made  many  other  experiments  of  the  same  hind  upon  the  in- 
crease of  the  thichness  of  the  neck  and  head  of  the  thigh  bone. 
From  thence  it  appeared  that  the  addition  of  new  matter  was  made 
to  the  upper  surface,  and  a proportional  quantity  of  the  old  removed 
from  the  lower,  so  as  to  keep  the  neck  of  the  same  form,  and  re- 
latively in  its  place.* 

To  ascertain  that  the  cylindrical  bones  are  not  elongated,  by 
new  matter  being  interposed  in  the  interstices  of  the  old,  he  made 
the  following  experiment : he  bored  two  holes  in  the  tibia  of  a pig, 
one  near  the  upper  end,  and  the  other  near  the  lower ; the  space 
between  the  holes  was  exactly  two  inches  : a small  leaden  shot 
was  inserted  into  each  hole.  When  the  bone  had  been  increased 
in  its  length  by  the  growth  of  the  animal,  the  pig  was  killed,  and 
the  space  within  the  two  shot  was  also  exactly  two  inches. 

This  experiment  was  repeated  several  times  on  different  pigs,  but 
the  space  between  the  two  shot  was  never  increased  during  the 
growth  of  the  bone.f 

* [Amongst  the  original  drawings  of  the  bones  coloured  by  madder  in  the 
Hunterian  experiments,  besides  those  of  the  thigh-bone  referred  to  in  the  text, 
there  are  three  which  illustrate  the  mode  and  direction  of  increase  of  the  lower 
jaw,  showing  that  the  new  bone  is  deposited  in  greatest  proportion  on  the  upper 
and  posterior  part  of  the  ascending  ramus,  by  which  the  rest  of  the  jaw  is  pushed 
forwards,  while  the  bone  is  absorbed  from  the  anterior  part  of  the  ramus,  and  thus 
the  sockets  of  the  posterior  grinders  are  gradually  brought  into  line,  with  a free 
space  above  for  the  teeth  to  come  forth.  This  mode  of  growth,  with  absorption 
at  the  symphisis  of  the  jaw,  continues  throughout  life  in  the  elephant,  in  which 
new  grinders  are  thus  brought  forwards  into  use  in  uninterrupted  succession. 

The  preparations  of  bones  coloured  with  madder  in  the  Hunterian  Collection 
are  as  follows.  Nos.  190  to  201  inclusive.  Physiological  Series  ; Nos.  742  to 
751,  Osteological  Series.] 

I [Meckel  has  rightly  observed  (supposing  the  above  to  be  a correct  statement 
of  Hunter’s  experiments  on  this  point),  that  they  are  invalidated  by  the  careful 
and  numerous  experiments  of  Duhamel,  which  prove  that  the  middle  portion  of 
the  long  bones  does  increase  in  length,  though  in  a less  degree  than  the  ex- 
tremities. 

It  is  not  easy  to  understand  how  the  unqualified  assertion  came  to  be  published, 
since  the  preparation  and  record  of  an  experiment  confirmatory  of  those  made  by 
Duhamel  are  still  preserved  in  the  Hunterian  Museum. 

The  preparation  (No.  188,  Physiological  Series),  is  the  left  tarso-metatarsal 
bone  of  a common  fowl,  exhibiting  two  perforations  at  equal  distances,  two  thirds 
of  a inch  from  the  extremities  of  the  bone.  The  original  record  of  the  experiment 
is  preserved  with  the  specimen. 


“ The  two  extreme  lines  are  the  present  length  of  the  bone  from  the  head  of  the 
joint  of  the  inner  toe,  The  two  inner  lines  are  the  length  when  cauterized.  The 
outer  dots  are  the  present  distance  or  the  holes  cauterized.  The  two  inner  dots 
are  the  distance  of  these  holes  when  cauterized;  so  that  the  bone  between  the 
two  holes  has  grown  about  two-eighths  of  an  inch,  while  the  other  parts  have 
grown  half  an  inch.” — Physiological  Catalogue,  vol.  i.,  p.  40. 

In  another  experiment,  in  which  shots  were  inserted  into  the  holes,  the  result 
was  spoiled  by  the  shots  passing  into  the  medullary  cavity  of  the  bone,  while 


322 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Besides  these  experiments  on  the  growth  of  bones,  he  made  others, 
to  determine  the  process  of  their  exfoliation.  He  cauterized  portions 
of  bone  in  the  same  way  in  several  different  animals,  so  as  to  be 
able  to  examine  the  bones  in  the  different  stages  of  this  process,  and 
found  that  the  earthy  part  of  the  living  bone  in  contact  with  the 
dead  portion  was  first  absorbed  ; afterwards  the  animal  mucilage 
itself,  so  as  to  form  a groove  between  the  two,  which  became 
deeper  and  deeper,  till  the  dead  bone  was  entirely  detached,  the  dead 
portion  itself  having  undergone  no  change.* 

From  these  experiments  he  ascertained  the  changes  which  take 
place  in  bones  during  their  growth,  and  the  readiness  with  which 
the  materials  of  bone  are  absorbed  ; and  from  these  facts,  laid  it 
down  as  an  established  principle,  that  the  absorbents  are  the  agents 
by  means  of  which  the  bones,  during  their  growth,  are  modelled 
as  it  were,  and  kept  of  the  same  shape. 

Bones,  according  to  Mr.  Hunter’s  doctrine,  grow'  by  two  pro- 
cesses going  on  at  the  same  time,  and  assisting  each  other;  the  ar- 
teries bring  the  supplies  to  the  bone  for  its  increase  ; the  absorbents 
at  the  same  time  are  employed  in  removing  portions  of  the  old  bone, 
so  as  to  give  to  the  new  proper  form.  By  these  means  the  bone 
becomes  larger,  without  having  any  material  change  produced  in 
its  external  shape.f 

the  perforations  became  obliterated,  as  in  Duhamel’s  experiment  with  the  ring 
of  wire,  by  the  deposition  of  new  bone  from  the  periosteum.  The  shots  being 
liberated  from  the  osseous  texture  could  no  longer  serve  to  indicate  its  growth. 
The  subject  of  the  experiment,  the  tarso- metatarsal  bone  of  a fowl,  is  No.  188, 
Physiological  Series.  It  is  remarkable  that  there  is  not  a single  prepara- 
tion of  the  long  bone  of  a pig,  exhibiting  the  experiments  with  shot  alluded  to  in 
the  text.  The  notes  of  the  experiments  on  the  bones  of  fowls  above  mentioned 
are  in  the  hand-writing  of  Mr.  Wm.  Pell,  Mr.  Hunter’s  talented  artist  and  assist- 
ant, and  must  therefore  have  been  written  in  or  before  the  year  1789,  when  Mr. 
Bell  left  England  for  the  East  Indies.] 

* [See  Preparations  Nos.  197  to  201  inclusive.  Pathological  Series.] 
t [The  difference  between  the  Hunterian  theory  of  the  growth  of  bone  and  that 
of  Duhamel  will  be  readily  appreciated  by  attending  to  the  explanation  given  by 
Duhamel  of  the  phrenomena  which  he  observed  dtiringhis  investigations  on  this 
subject.  Let  us,  for  example,  select  from  the  number  of  his  ingenious  and  in- 
structive experiments,  that  in  which  he  placed  a ring  of  silver  wire  round  the 
middle  of  the  shaft  of  the  thigh-bone  of  a young  pigeon  ; and  found  at  a subse- 
quent period  the  ring  in  the  medullary  cavity  of  the  bone,  instead  of  embracing 
the  exterior  of  the  shaft,  where  he  had  placed  it.  It  need  scarcely  be  observed 
that  the  Hunterian  physiologist  would  explain  these  facts  by  stating  that  the 
arteries  of  the  periosteum  had  deposited  new  hone  on  the  external  surface  of  the 
ring,  while  the  absorbents  had  removed  the  old  bone  in  contact  with  the  internal 
surface  of  the  ring,  by  which  its  relations  to  the  os.seous  parietes  of  the  femur 
became  reversed.  But  this  physiological  view  of  the  phaenomena,  arising  out  of 
a knowledge  of  the  powers  and  actions  of  great  and  important  vascular  systems 
in  the  frame,  was  wholly  unsuspected  by  and  unknown  to  the  predecessors  of 
Hunter.  Duhamel  explains  the  facts  on  mechanical  principles  ; assuming  that 
the  bony  layers  of  the  shaft  of  the  thigh-bone  were  expanded  by  the  interposition 
of  additional  osseous  matter,  and  that  the  layers  wmre  cut  through  in  this  process 
of  expansion  by  the  unyielding  wire  which  he  had  placed  around  them.  All  his 
explanations  bear  the  same  mechanical  character,  in  which  processes  of  growth 
are  assumed  which  are  negatived  by  observation;  and  they  are  frequently  vitiated 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


323 


32.  OBSERVATIONS  TENDING  TO  SHOW  THAT  THE 
WOLF,  JACKAL,  AND  DOG,  ARE  ALL  OF  THE 
SAME  SPECIES. 

The  true  distinction  between  different  species  of  animals  must 
ultimately,  as  appears  to  me,  be  gathered  from  their  incapacity  of 
propagating  with  each  other  an  offspring  capable  again  of  continu- 
ing itself  by  subsequent  propagations  : thus  the  horse  and  ass  beget 
a mule  capable  of  copulation,  but  incapable  of  begetting  or  pro- 
ducing offspring.  If  it  be  true  that  the  mule  has  been  known  to  breed, 
which  must  be  allowed  to  be  an  extraordinary  fact,  it  will  by  no 
means  be  sufficient  to  determine  the  horse  and  ass  to  be  of  the 
same  species  ; indeed,  from  the  copulation  of  mules  being  very 
frequent,  and  the  circumstance  of  their  breeding  very  rare,  I should 
rather  attribute  it  to  a degree  of  monstrosity  in  the  organs  of  tlie 
mule  which  conceived,  as  not  being  a mixture  of  two  different 
species,  but  merely  those  of  either  the  marc  or  female  ass.  This 
is  not  so  far-fetched  an  idea,  when  we  consider  that  some  true 
species  produce  monsters,  which  are  a mixture  of  both  sexes,  and 
that  many  animals  of  distinct  sex  are  incapable  of  breeding  at 
all.'  If  then  we  find  Nature  in  its  most  perfect  state  deviating  from 
general  principles,  why  may  it  not  happen  likewise  in  the  produc- 
tion of  mules;  so  that  sometimes  a mule  shall  breed  from  the  cir- 
cumstance of  its  being  a monster  respecting  mules'? 

The  time  of  uterine  gestation  being  the  same  in  all  the  varieties 
of  every  species  of  animals,  it  becomes  a necessary  circumstance 
towards  determining  a species. 

The  affinity  between  the  fox,  wolf,  jackal,  and  several  varieties 
of  the  dog,  in  their  external  form  and  several  of  their  properties,  is 
so  striking,  that  they  appear  to  be  only  varieties  of  the  same  species. 
The  fox  would  seem  to  be  further  removed  from  the  dog  than  either 
the  jackal  or  wolf,  at  least  in  disposition,  being  naturally  a solitary 
animal,  and  neither  so  sociable  respecting  its  own  species  or  man  ; 
from  which  I should  infer  that  it  is  only  allied  to  the  dog  by  being 
of  the  same  genus.  It  is  confidently  asserted  by  many  that  the  fox 
breeds  with  the  dog;  but  this  has  not  been  accurately  ascertained  ; 
if  it  had,  the  inquiry  would  probably  have  been  carried  further; 
and  once  breeding,  according  to  what  we  have  said,  does  not  con- 
stitute a species  ; this,  however,  is  a part  I mean  to  investigate.  I 
do  not  know  if,  in  a wild  state,  there  ever  is  in  the  same  country  a 

by  overstrained  analogies,  as  where,  in  explaining  the  process  of  union  in  a frac- 
tured bone,  he  connpares  the  periosteum  to  the  bark  of  trees.  But  the  numerous 
experiments  of  Duhamel,''  which  are  characterized  by  much  precision  and  in- 
genuity, well  merit  the  attention  of  the  student  of  Physiology.] 


[Sur  le  development  et  la  crue  des  os.  Memoires  de  I’Acad.  des  Sciences. 
Paris,  1742,  p.  497  ; and  1743,  p.  187.] 


324 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


variety  in  any  species  of  animal,  but  am  inclined  to  think  there 
never  is  ; if  so,  as  both  wolves  and  foxes  inhabited  this  country, 
they  cannot  then  be  of  the  same  species. 

Wolves,  as  also  jackals,  are  found  in  herds;  and  the  jackal  is 
so  little  afraid  of  the  human  species,  that,  like  a dog,  it  comes  into 
houses  in  search  of  food,  more  like  a variety  of  the  dog,  the  con- 
sequence of  cultivation  rather  than  of  chance.  It  would  appear  to 
be  much  the  most  familiar  of  the  two;  for  we  shall  find  that  in  its 
I'eadiness  to  copulate  with  the  dog,  and  its  familiarity  with  the  dog 
afterwards,  it  is  somewhat  different  from  the  wolf;  however,  this 
may  depend  on  accident.  The  wolf  being  an  animal  well  known 
in  Europe,  the  part  of  the  world  where  natural  history  is  particu- 
larly cultivated,  some  pains  have  been  taken  to  ascertain  whether 
or  not  it  was  of  the  same  species  with  the  dog;  but  I believe  it  has 
been  hitherto  considered  as  only  belonging  to  the  same  genus. 

Accident  often  does  as  much  for  natural  history  as  premeditated 
plans,  especially  when  Nature  is  left  to  herself.  The  first  instance 
of  the  dog  and  wolf  breeding  in  this  country  seems  to  have  been 
about  the  year  1706.  A Pomeranian  bitch  of  Mr.  Brookes’s,  in 
the  New  Ifoad,  was  lined  only  once  by  a wolf,  and  brought  forth  a 
litter  of  nine  healthy  puppies.  The  veracity  of  Mr.  Brookes  is  not 
to  be  doubted,  respecting  the  bitch  having  been  lined  by  a wolf; 
yet  as  it  was  possible  she  might  have  been  lined  by  some  common 
dog  without  his  knowledge,  the  fact  was  not,  in  that,  clearly  made 
out;  but  it  has  since  been  ascertained  that  the  dog  and  wolf  will 
breed.  One  of  the  above-mentioned  litter  Mms  presented  to  me  by 
Mr.  Brooks,  who  likewise  informed  me  that  others  had  been  pur- 
chased by  different  noblemen  and  gentlemen,  and  named  Lord 
Clanbrassil  as  having  bought  a bitch  puppy.  I reserved  mine  for 
the  purpose  of  experiment;  and  from  observation  it  appeared  that 
its  actions  were  not  trulj^  those  of  a dog,  having  more  quickness  of 
attention  to  what  passed,  being  more  easily  startled,  as  if  particu- 
larly apprehensive  of  danger,  quicker  in  transitions  from  one  action 
to  another,  being  not  so  ready  to  the  call,  and  less  docile.  From 
these  peculiarities  it  lost  its  life,  having  been  stoned  to  death  in  the 
streets  for  a mad  dog. 

Hearing  that  Lord  Clanbrassil’s  bitch  had  bred.  Sir  Joseph  Banks 
was  so  obliging  as,  at  my  request,  to  write  to  his  Lordship,  who 
sent  the  following  account : 

“ Sir, 

“ About  seventeen  or  eighteen  years  ago,  the  late  Lord  Mon- 
thermer  and  I happened  to  see  a dog-wolf  at  Mr.  Brookes’s,  who 
deals  in  animals,  and  lives  in  New  Road.  The  animal  was  re- 
markably tame,  and  it  struck  us,  for  that  reason,  that  a breed 
might  be  procured  between  him  and  a bitch. 

“ We  promised  Mr.  Brookes  a good  price  for  puppies  if  he  suc- 
ceeded. In  about  a year  a bitch  produced  nine,  and  Lord  Mon- 
thermer  bought  one ; and  I had  another,  which  was  a bitch.  Lord 
Monthermer’s  died  of  fits  in  about  two  years  : mine  lived  longer,  and 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


325 


had  puppies  only  once.  One  I gave  to  Lord  Pembroke,  but  what 
became  of  it  I do  not  remember.  It  was  granddaughter  of  the  wolf 
by  the  dam,  and  got  by  a large  pointer  of  mine. 

“ It  might  be  considered  that  Mr.  Brookes’s  word  was  not  suf- 
ficient proof  that  the  puppies  were  really  got  by  the  wolf,  but  the 
appearance  of  the  animals,  so  totally  diflerent  from  all  others  of  the 
canine  species,  did  not  leave  a doubt  upon  our  minds ; and  I re- 
member Hans  Stanley,  who  had  adopted  BufFon’s  opinion,  was 
thoroughly  convinced  upon  seeing  mine.  The  animals  had  the 
shape  of  the  wolf  refined  ; the  fur  long,  but  almost  as  fine  as  that 
of  the  black  fox. 

“ I am  afraid  I have  trespassed  too  much  upon  your  time,  and 
will  only  beg  you  will  be  assured  nothing  can  give  me  more  pleasure 
than  any  opportunity  of  assuring  you  how  truly 

“ I am,  sir,  &c. 

“ Jan.  7, 1787.  “ Clanbrassil.” 

Upon  the  supposition  that  Mr.  Brookes’s  bitch  was  not  lined  by  a 
dog,  but  by  the  wolf,  which  I think  we  have  no  reason  to  doubt,  the 
species  of  the  wolf  is  ascertained;  but  choosing  to  trace  this  matter 
still  further,  and  hearing  that  Lord  Pembroke’s  bitch  had  likewise 
bred,  I was  desirous  to  know  the  truth  of  it ; and  as  his  lordship 
was  in  France  I took  the  liberty  of  writing  to  Lord  Herbert,  and 
received  the  following  answer : 

“Sir,  Wilton  House,  Dec.  20,  1786. 

“ The  half-bred  wolf-bitch  you  allude  to  was  given,  as  I always 
understood,  to  Lord  Pembroke  by  Lord  Clanbrassil.  She  might, 
perhaps,  have  been  bought  at  Brookes’s  by  him.  She  had  four 
litters,  one  of  ten  puppies,  by  a dog  between  a mastiff  and  a bull-dog. 
One  of  these  was  given  to  Dr.  Eyre,  at  Wells  in  Somersetshire,  and 
one  to  Mr.  Buckett  at  Stockbridge.  The  second  litter  was  of  nine 
puppies,  some  of  which  were  sent  to  Ireland,  but  to  whom  1 know 
not.  This  litter  w'as  by  a different  dog,  but  of  the  same  breed  as  the 
first.  The  third  litter  was  of  eight  puppies,  by  a large  mastiff. 
Two  of  these  w’ere,  1 believe,  sent  to  the  present  Dukeof  Queensberry. 
The  fourth  litter  consisted  of  seven  puppies,  two  of  which  were  sent 
to  M.  Cerjat,  a gentleman  who  now  resides  at  Lausanne  in  Switzer- 
land, and  is  famous  for  breaking  dogs  remarkably  well.  These 
two  puppies  w'ere,  however,  naturally  so  wild  and  unruly,  that 
he  found  it  impossible  to  break  them. 

She  died  four  years  ago,  and  the  following  inscription  was  put 
over  the  place  where  she  is  buried  in  this  garden,  by  Lord  Pem- 
broke’s orders : 

Here  lies  Lupa, 

whose  grandmother  was  a wolf, 
whose  father  and  grandfather  were  dogs,  and  whose 
mother  was  half  wolf  and  half  dog.  She  died 
on  the  16th  of  October,  1782, 
aged  12  years. 

29' 


326 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


“ I am  sorry  it  is  not  in  my  power  to  give  you  any  better  account ; 
but  if  you  think  proper  to  write  to  Lord  Pembroke,  who  is  at  Paris, 
I am  convinced  he  will  be  very  happy  to  give  you  any  further  in- 
formation. 

“ I am,  &c. 

“ Herbert.” 

Buffbn,  whose  remarks  in  natural  history  are  well  known,  made 
experiments  to  ascertain  how  far  the  wolf  and  dog  were  of  the 
same  species,  but  without  success.  Pie  says,  “ A she-wolf,  which 
I kept  three  years,  although  shut  up  very  young,  and  along  with  a 
greyhound  of  the  same  age,  in  a spacious  yard,  could  not  be  brought 
to  agree  with  it,  nor  endure  it,  even  when  she  was  in  heat.  She 
was  the  weakest,  yet  the  most  mischievous,  provoking,  attacking, 
and  biting  the  dog,  which  at  first  only  defended  itself,  but  at  last 
killed  her.”  And  in  another  part  of  his  work  he  makes  the  following 
observation  : “ The  dog,  the  wolf,  the  fox,  and  the  jackall,  form  a. 
genus,  of  which  the  diflerent  species  are  really  so  nearly  allied  to 
each  other,  and  of  which  the  individuals  resemble  each  other  so 
much,  particularly  by  the  internal  structure  and  parts  of  generation, 
that  it  is  difficult  to  conceive  why  they  do  not  breed  together.”* 

This  part  of  natural  history  lay  dormant,  till  Mr.  Gough,  who 
sells  birds  and  has  a collection  of  animals  on  Holborn-hill,  repeated 
the  experiment  on  a wolf-bitch,  which  was  very  tame,  and  had  all 
the  actions  of  a dog  under  confinement.  A dog  is  the  most  proper 
subject  for  comparison,  as  we  have  opportunities  of  being  acquainted 
with  its  disposition  and  mode  of  expressing  its  sensations,  which 

* In  the  Supplement  to  his  Works  he  gives  the  following  account  wliich  had 
been  sent  to  him.  “ A very  young  she-wolf,  brought  up  at  the  Marquis  of  Spon- 
tin’s,  at  Namur,  had  a dog,  of  nearly  the  same  age,  kept  with  it  as  a companion. 
For  two  years  they  were  at  liberty,  coming  and  going  about  the  apartments,  the 
kitchen,  the  stables,  &c.,  lying  under  the  table,  and  upon  the  feet  of  those  who 
sat  round  it.  They  lived  in  the  greatest  familiarity. 

“ The  dog  was  a strong  greyhound.  The  wolf  was  fed  on  milk  for  six  months  ; 
after  that,  raw  meat  was  given  her,  which  she  preferred  to  that  which  was  dressed. 
When  she  ate  no  one  durst  approach  her,  but  at  other  times  people  might  do  as 
they  pleased,  provided  they  did  not  use  her  ill.  At  first  she  made  much  of  all 
the  dogs  which  were  brought  to  her,  but  afterwards  she  gave  the  preference  to 
her  old  companion,  and  from  that  time  she  became  very  fierce  if  any  strange  dog  ap- 
proached her.  She  W’as  lined  for  the  first  time  on  the  25th  of  March  ; this  was 
frequently  repeated  while  her  heat  continued,  w’hich  was  sixteen  days;  and  she 
littered  the  6th  of  June,  at  eight  o’clock  in  the  morning ; the  period  of  gestation 
was  therefore  seventy-three  days  at  the  most.a  She  brought  forth  four  young 
ones  of  a blackish  colour,  some  of  whose  feet,  and  a part  of  the  breast,  were 
white  ; in  this  respect  taking  after  the  dog,  which  was  blackand  white.  From  the 
time  she  littered  she  became  surly,  and  set  up  her  back  at  those  who  came  near 
her ; did  not  know  her  masters,  and  would  even  have  killed  the  dog  if  it  had  been 
in  her  power,” 


“ This  is  a longer  period  than  in  the  bitch  by  at  least  ten  days,  but  as  the  ac- 
count was  made  from  the  first  time  of  her  being  lined,  and  she  was  in  heat  for  a 
fortnight,  arid  lined  in  that  time,  it  is  very  probable,  if  the  time  was  known  when 
she  conceived,  that  it  would  prove  to  be  the  same  period  as  in  the  dog. 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


327 


are  most  distinguishable  in  the  motion  of  the  ears  and  tail ; such  as 
pricking  up  the  ears  when  anxious,  wishing,  or  in  expectation ; 
depressing  them  when  supplicant  or  in  fear  ; raising  the  tail  in 
anger  or  love,  depressing  it  in  fear,  and  moving  it  laterally  in 
friendship ; and  likewise  in  raising  the  hair  on  the  back  from  many 
affections  of  the  mind.  This  animal  became  in  heat  in  the  month 
of  December  1785;  and  Mr.  Gough  having  an  idea  of  obtaining  a 
breed  from  wild  animals,  as  monkies,  leopards,  &c.,  he  was  desirous 
to  have  the  wolf  lined  by  some  dog;  but  she  would  not  allow  any 
dog  to  come  near  her,  probably  from  being  always  chained,  and 
not  accustomed  to  be  with  dogs.  She  was  held,  however,  while  a 
greyhound  dog  lined  her,  and  they  fastened  together  exactly  like 
the  dog  and  bitch.  While  in  conjunction  she  remained  pretty  quiet, 
but  when  at  liberty  endeavoured  to  fly  at  the  dog  ; yet  in  this  way 
was  twice  lined.  She  conceived,  and  brought  forth  four  young 
ones;  and  though  the  time  she  went  with  young  was  not  exactly- 
known,  it  was  believed  to  be  the  same  as  in  the  bitch.  Two  of 
these  puppies  were  like  the  dog  in  colour,  who  had  large  black  spots 
on  a white  ground  ; another  was  of  a black  colour  ; the  fourth  of 
a kind  of  dun,  and  would  probably  have  been  like  the  mother.* 
She  took  great  care  of  them,  yet  did  not  seem  very  anxious  when 
one  was  taken  from  her  by  the  keeper ; nor  did  she  seem  afraid 
when  strangers  came  into  the  room.  Unfortunately  these  experi- 
ments were  carried  no  further : one  of  the  puppies  being  sold  to  a 
gentleman,  who  carried  it  to  the  East  Indies  ; and  the  other  three, 
one  of  which  I was  to  have  had,  were  killed  by  a leopard.  The 
same  wolf  was  in  heat  in  December  1786,  and  was  lined  several 
times  by  a dog.  She  pupped  on  the  24th  of  February  1787,  and 
had  six  puppies,  one  of  which,  a bitch,  I had,  and  kept  it  till  it 
was  in  heat ; but  missed  the  opportunity  of  having  her  lined.  That 
loss,  however,  was  made  up  by  a wolf-bitch  belonging  to  James 
Syrnmons,  Esq.,  of  Grosvenor-house,  Milbank:  the  history  of 
which  is  as  follows  : 

This  female  wolf  had  been  in  his  possession  some  time,  had  been 
lined  by  a dog,  and  brought  forth  several  puppies,  which  I saw  in 
company  with  Sir  Joseph  Banks,  soon  after  Mr.  Gough’s  wolf,  the 
subject  of  my'  former  paper,  had  produced  her  litter;  so  that  these 
puppies  were  nearly  of  the  same  age  with  mine.  Mr.  Syrnmons 
reared  them  all ; but  one  oifly  was  a female,  which  more  resembled 
the  mother  or  wolf  kind  than  any'  of  the  others.  I communicated 

* [Here  it  may  be  observed,  that,  from  the  known  disposition  of  varieties  to 
revert  to  the  original,  it  might  have  been  expected,  on  the  supposition  tliat  the 
wolf  is  the  original  of  the  dog,  that  the  produce  of  the  wolf  and  dog  ought  rather 
to  have  resembled  the  supposed  original  than  the  variety.  Tn  a litter  lately  ob- 
tained, in  the  Royal  Menagerie  at  Berlin,  from  a white  pointer  and  a she-wolf, 
two  of  the  cubs  resembled  the  common  wolf-dog,  but  the  third  was  like  a pointer 
with  hanging  ears.®] 


^ [Lyell,  Principles  of  Geology,  vol.  ii.,  p.  438,  who  cites  Wiegmann  for  this 
fact.] 


328 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


to  Mr.  Symmons  my  wish  that  we  should  endeavour  to  prove  the 
fact  of  the  wolf  and  dog  being  of  the  same  species,  by  having 
either  his  female  or  mine  lined  by  a dog.  This  he  very  readily 
acceded  to;  and  his  bitch  received  the  dog  on  the  16th,  17th,  and 
18th  of  December,  1788;  and  the  18th  of  February  following  she 
brought  forth  eight  puppies,  all  of  which  she  reared. 

If  we  reckon  from  the  16th  of  December,  she  went  sixty-four 
days  ; but  if  we  reckon  from  the  17th,  the  mean  time,  then  it  is 
sixty-three  days,  the  usual  time  for  a bitch  to  go  with  pup.  These 
puppies  are  the  second  remove  from  the  wolf  and  dog,  and  similar 
to  that  given  by  my  Lord  Clanbrassil  to  the  Earl  of  Pembroke, 
which  likewise  bred  again.  (See  Philosophical  Transactions, 
vol.lxxvii.,  p.  255.)  It  would  have  equally  proved  the  same  fact  if 
she  had  been  lined  either  by  a wolf,  a dog,  or  one  of  the  males  of 
her  own  litter.* 

It  is  remarkable  that  there  seems  to  be  only  one  time  in  the  year 
in  which  impregnation  is  natural  to  the  wolf,  which  is  the  month  of 
December:  for  Mr.  Gough’s  wolf  has  always  been  in  heat  in  that 
month  ; so  was  that  of  Mr.  Simmons.  The  time  of  heat  in  his  of 
the  half-breed  (which  is  nearly  of  the  same  age  with  mine)  corres- 
ponded likewise  with  that  of  the  mother,  and  of  those  bred  from 
Mr.  Gough’s  wolf. 


OF  THE  JACKAL. 

This  animal  being  so  nearly  allied  to  the  dog,  and  only  found 
wdld  like  the  w’olf,  I became  desirous  of  ascertaining  of  what  par- 
ticular species  it  was ; and  while  pursuing  the  subject,  I was  in- 
formed that  Captain  Mears,  of  the  Royal  Bishop,  East  Indiaman, 
had  brought  home  a bitch-jackal  with  young,  which  brought  forth 
soon  after  his  arrival ; and  that  he  had  given  the  bitch-jackal  and 
one  puppy  to  Mr.  Bailey,  bird-merchant,  in  Piccadilly.  I went  to 
see  them,  and  purchased  the  puppy,  the  subject  of  the  following  ex- 
periment, which  we  found  to  have  dispositions  very  similar  to  those 
of  the  half-bred  wolf  before-mentioned,  which  I had  from  Mr. 
Brookes. 

* [This  assertion,  that  the  fertility  of  a hybrid  with  an  individual  of  a pure 
breed  proves  the  fact  of  identity  of  two  supposed  distinct  species  equally  with 
the  production  of  offspring  from  the  connection  of  hybrid  with  hybrid,  cannot  be 
admitted.  To  prove  the  identity  of  two  supposed  distinct  species,  granting  that 
the  fertility  of  the  hybrids  from  the  two  to  be  the  proof  required,  it  should  be 
shown  that  such  hybrids  are  fertile  into' se,  and  capable  of  propagating  indefinitely 
an  intermediate  variety.  Now  this  is  precisely  the  fact  which  is  wanting  in  the 
evidence  adduced  in  the  text.  All  that  Hunter  proves  is  that  two  species  very 
nearly  allied  to  each  other  will  produce  a hybrid  offspring,  and  that  the  hybrid  is 
again  productive  with  an  individual  of  the  jture  breed  ; but  this  only  illustrates 
a general  law  by  which  the  reversion  of  the  hybrid  to  the  pure  breed  is  provided 
for  : while,  on  the  other  hand,  the  intermixture  of  the  distinct  species  is  guarded 
against  by  the  aversion  of  the  individuals  composing  them  to  sexual  union  : an 
aversion  which  we  see  in  the  case  of  Mr.  Gough’s  female  wolf  to  have  been  only 
overcome  by  force.] 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


320 


To  have  a true  history  of  this  animal,  I took  the  liberty  of  writing 
to  Mr.  Mears,  who  politely  called  upon  me,  and,  at  my  request,  sent 
me  the  particulars  in  a letter,  of  which  the  following  is  a copy  : 

“ Sir, 

“ I had  the  honour  of  yours  of  the  15th  instant ; and  with  regard 
to  the  female-jackal,  I can  assure  you  that  she  took  a small  spaniel 
dog  of  mine  on  board  my  ship,  the  Royal  Bishop.  I had  her, 
when  a cub,  at  Bombay  ; and  a very  short  time  before  I arrived  in 
England  she  got  to  heat,  and  enticed  this  small  dog  into  the  long- 
boat, where  I saw  them  repeatedly  fast  together.  I brought  her  to 
my  house  in  the  country,  where  she  pupped  six  puppies,  one  of 
which  you  have  seen.  Mr.  Flaw,  at  No.  90,  Tottenham-court 
Road,  has  a dog-puppy,  which  will  be  at  your  service  at  any  time 
you  chuse  to  send  for  him,  to  make  further  experiments  : I called 
on  Mr.  Flaw,  and  got  his  promise  to  let  you  have  the  dog. 

“ I have  the  honour  to  be,  sir,  &c. 

“Wm.  Mears. 

“ No.  107,  Hattoii-street,  16th  Jan.  1786. 

“F. S.  I had  the  bitch  on  board  fourteen  months.” 

Having  taken  this  puppy  into  the  country,  and  chained  it  up  near 
a mastiff-dog,  they  became  very  familiar,  and  seemingly  fond  of 
each  other.  When  the  bitch  became  first  in  heat  I could  not  get  a 
proper  dog:  but  about  the  latter  end  of  September,  she  being  again 
in  the  same  state,  several  dogs  were  procured  and  left  with  her. — 
They  appeared  indifierent  about  her,  probably  from  being  in  a 
strange  place;  nor  did  she  seem  inclined  to  be  familiar  with  them. 
One  of  them  was  a large  dog,  which  might  not  perhaps  be  able  to 
line  her;  but  she  was  twice  tied  by  a terrier  on  the  3d  of  Octo- 
ber. In  a few  weeks  she  was  evidently  bigger;  and  on  the  30th 
of  November,  in  all  fifty-nine  days,  brought  forth  five  puppies.  A 
few  days  before  this  period  she  dug  a hole  in  the  ground,  by  the 
side  of  her  kennel,  in  w'hich  she  littered;  and  it  was  some  time  be- 
fore she  would  allow  the  puppies  to  stay  in  the  kennel  when  put 
there.  Some  of  these  began  to  open  their  eyelids  in  about  eight, 
others  of  them  in  nine  days. 

Here  then  being  an  absolute  proof  of  the  jackal  being  a dog,  and 
the  wolf  being  equally  made  out  to  be  of  the  same  species,  it  now 
therefore  becomes  a question  whether  the  wolf  is  from  the  jackal, 
or  the  jackal  from  the  wolf  (supposing  them  but  one  origin)  ? From 
the  supposition  that  varieties  become  more  tame  in  their  nature 
than  the  originals,  we  should  be  led  to  believe  the  wolf  to  be  the 
original,  and  that  the  jackal  was  a step  towards  civilization  in  that 
species  of  animal,  and  that  therefore  the  jackal  should  be  considered 
as  a variety  of  the  wolf.  There  are  wolves  of  various  kinds,  each 
country  having  a kind  peculiar  to  itself ; but  the  jackals  that  I have 
seen  have  been  more  uniform  in  resemblance  to  each  other,  proba- 
bly because  only  to  be  found  in  one  country,  the  East  Indies.  I 
am  informed,  however,  that  they  vary  in  size..  Whether  the  W'olves 

29* 


330 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


of  diflerent  countries  are  of  one  species,  or  some  of  tl)em  only  of 
the  same  genus,  I do  not  know;  but  I should  rather  suppose  them 
to  be  all  of  one  species.  An  argument  with  me  in  favour  of  this  sup- 
position is,  that  if  there  were  wolves  of  distinct  species,  we  should 
have  had  by  this  time  a great  variety  of  every  species  of  wolf, 
with  the  various  dispositions  arising  from  variation  in  other  respects; 
and  those  varieties  would  now  have  been  turned  to  very  useful  pur- 
poses, as  in  the  case  of  the  dog:  for  all  the  wolves  we  are  yet  ac- 
quainted with  should  have  naturally  the  principle  of  cultivation  in 
them  (as  much  probably  as  any  anim.al),  as  much  at  least  as  those 
wolves  we  now  know  by  the  name  of  dogs.  The  not  having  a civil- 
ized species  with  all  the  characteristics  of  the  wolf  is,  indeed,  with 
me  a proof  that  they  are  all  of  the  same  species  with  the  dog.  If 
they  are  all  of  the  same  species  with  the  dog,  then  the  first  variety 
that  took  place  would  be  still  in  the  character  of  a wolf,  differing 
only  in  colour  or  some  trivial  circumstance,  which  could  only  arise 
from  a difference  in  climate.  The  wolf  is  naturally,  I believe,  the 
inhabitant  of  cold  climates,  and  little  variety  could  take  place  while 
it  remained  in  such  a situation;  but  if  the  jackal  was  originally  a 
wolf,  which  had  strayed  by  accident  more  to  the  southward,  a 
greater  variation  from  the  genuine  character  might  be  produced, 
the  difference  of  climate,  and  perhaps  of  food,  becoming  causes  of 
variety.  By  continuing  to  inhabit  a warm  climate,  this  circum- 
stance would  in  time  lose  part  of  its  influence  on  the  animal,  and 
the  jackal  would  admit  of  little  more  variety.  This,  however,  is  a 
point  not  now  to  be  determined,  it  being  difficult  (perhaps  impossi- 
ble) to  say  where  the  wolf  became  jackal,  or  (what  we  call)  dog; 
and,  as  dogs  differ  much  from  one  another,  what  particular  dog 
may  be  considered  as  the  first  remove;  or  whether  the  jackal  is 
the  intermediate  link  connecting  the  wolf  and  dog.  In  any  case  we 
may  reckon  three  great  varieties  in  this  species,  wolf,  jackal,  and 
dog;  which  again  branch  into  their  respective  less  obvious  varieties. 
If  the  dog  proves  to  be  the  wolf  tamed,  the  jackal  may  probably  be  the 
dog  returned  to  it  s’ wild  state ; which  leads  to  another  curious  question: 
Whether,  as  animals  vary  from  climate,  cultivation,  or  what  may 
be  called  differences  in  mode  of  living,  they  would  return  to  their 
genuine  character  if  allowed  to  go  wild  again  in  the  original  country  ? 

To  ascertain  the  original  animal  of  a species,  all  the  varieties  of 
that  species  should  be  examined,  to  see  how  far  they  have  the  cha- 
racter of  the  genus,  and  what  resemblance  they  bear  to  the  other 
species  of  the  genus;  for  it  is  natural  to  suppose  that  the  original 
animal,  or  that  which  is  nearest  to  it,  will  have  more  of  the  true 
character  of  the  genus,  and  a stronger  resemblance  to  the  species 
nearest  allied  to  it,  than  any  of  the  other  varieties  of  its  own 
species. 

If  we  apply  this  to  the  dog,  and  consider  the  fox  as  a distinct 
species,  which  there  is  great  reason  to  believe  it  is,  that  variety 
which  has  the  greatest  resemblance  to  the  fox  is  to  be  looked  upon 
as  the  original  of  all  the  others : which  will  prove  to  be  the 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


331 


Another  mode  of  considering  this  subject,  •which  is,  however, 
secondary  to  the  above,  is  by  supposing  that  all  animals  were  at 
first  wild  ; and  therefore  that  those  animals  which  remain  wild  are 
the  original  stock  ; and  that  when  we  find  animals  far  removed  from 
their  originals  in  appearance  the  variation  takes  place  in  conse- 
quence of  cultivation,  yet  so  that  we  can  still  trace  the  gradation. 
What  gives  some  force  to  this  idea  is,  that  where  the  dogs  have 
been  least  cultivated,  there  they  still  retain  most  of  their  original 
character,  or  similarity  to  the  wolf  or  the  jackal,  both  in  shape  and 
disposition.  The  shepherd’s  dog,  all  over  the  world,  has  strongly 
the  character  of  the  wolf  or  jackal ; so  that  but  little  difi'erence  is 
to  be  observed,  except  in  size  and  hair.  That  of  size  may  perhaps 
take  place  under  a variety  of  circumstances  ; but  difi'erence  in  hair 
is  in  general,  although  not  always,  influenced  by  climate.  Thus  the 
wolf  has  longer  and  softer  hair  than  the  jackal,  because  a more 
northern  animal;  while  the  jackal  of  the  East,  and  the  shepherd’s 
dog  in  Portugal  and  Spain,  have  shorter  and  stronger  hair  than 
those  of  Germany  or  Kamtschatka,  from  inhabiting  warmer 
climates.  But  when  we  consider  their  general  shape,  the  character 
of  countenance,  the  quick  manner,  with  the  pricked  and  erect  ears, 
we  must  suppose  them  varieties  of  the  same  species.  The  smelling 
at  the  tail  has  been  mentioned  as  characteristic  of  the  dog;  but  I 
believe  it  is  common  to  most  animals,  and  only  marks  the  male,  for 
it  is  the  most  certain  way  the  male  has  of  knowing  the  female,  and 
by  another  scent  discovering  whether  the  female  is  disposed  to 
receive  the  male,  which  is  perhaps  the  final  intention. 

The  Esquimaux  dog,  and  that  found  among  the  Indians  as  far 
south  as  the  Cherokees,  the  shepherd’s  dog  in  Germany,  called 
Pomeranian,  the  shepherd’s  dog  in  Portugal  and  Spain,  have  all  a 
strong  similarity  to  the  wolf  and  jackal. 

Buft’on,  on  the  origin  of  dogs,  seems  to  have  had  nearly  the  same 
idea  : for  he  says  the  shepherd’s  dog  is  the  original  stock  from 
which  the  different  kinds  of  dog  have  sprung. 

As  the  wolf  turns  out  to  be  a dog,  it  seems  astonishing  that  there 
was  no  accounkof  dogs  being  found  in  America.  But  this  I consi- 
der as  a defect  in  the  first  history  of  that  country,  as  there  are 
wolves  ; and  I must  think,  in  spite  of  all  that  has  been  said  to  the 
contrary,  that  the  Esquimaux  and  Indian  dog  is  only  a variety  from 
a wolf  of  that  country  which  had  been  tamed.  Mr.  Cameron,  of 
Titchfield-street,  who  was  many  years  among  the  Cherokees,  and 
considerably  to  the  westward  of  that  country,  observes  that  the  dog 
found  there  much  resembles  the  wolf,  and  that  the  natives  consider 
it  to  be  a species  of  tame  wolf;  but  as  we  come  more  among  the 
Europeans  who  have  settled  there,  the  dogs  are  more  of  a mixed 
breed.  Why  the  Cherokees  should  have  had  only  this  kind  of  dog 
transported  among  them,  while  every  other  part  of  America  has  the 
varieties  of  Europe,  is  not  easily  solved. 

The  voice  of  animals  is  commonly  characteristic  of  the  species; 
but  I should  suppose  it  to  be  only  characteristic  of  the  original  spe- 


332 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


cies,  and  not  always  of  the  variety,  and  the  supposition  holds  good 
in  the  dog  species.  Dogs  may  be  said  to  have  a natural  voice 
and  a variation,  arising  either  from  a variety  having  taken 
place  in  the  species,  or  a kind  of  imitation.  It  would  appear  that 
the  voice  of  the  wolf  and  the  jackal  is  very  similar,  being  the 
natural  voice,  and  is  principally  conveyed  through  the  nose,  and  ex- 
actly resembling  that  noise  in  dogs  which  is  a mark  of  longing  or  me- 
lancholy and  also  of  fondness, but  having  no  resemblance  to  the  bark 
of  the  dog,  which  they  do  not  perform.  However,  in  catching  a 
jackal,  when  the  animal  found  it  could  not  escape,  it  yelped  like  the 
dog,  which  is  a kind  of  barking,  and  which  is  probably  the  natural 
sound.  Barking  is  peculiar  to  certain  varieties  of  the  dog  kind, 
and  even  of  those  that  bark  some  do  it  less  than  others : the  dogs 
in  the  South  Sea  Islands  do  not  bark,  our  greyhound  barks  but 
little,  while  the  mastiff'  and  many  of  the  smaller  tribe,  as  spaniels, 
are  particularly  noisy  in  this  way.  There  is  reason  to  believe  that 
the  frequency  of  this  noise  may  arise  from  imitation  : for  the  dogs 
in  the  South  Sea  Islands  learn  to  bark,  the  half-breed  jackal  barked, 
and  so  did  the  half-breed  wolf,  although  but  little;  and  others,  as 
the  hound,  have  a peculiar  howl,  by  huntsmen  called  the  tongue, 
which  noise,  and  the  barking  also,  are  both  made  by  opening  the 
mouth.  A variety  in  the  voice,  or  some  parts  of  the  voice,  in  varie- 
ties of  the  same  species,  is  not  peculiar  to  the  dog. 

It  is  a curious  circumstance  that  variety  not  only  takes  place  in 
colour  and  form,  from  the  change  of  habits  in  the  parents,  but  that 
the  dispositions  are  also  changed;  and  that  the  dispositions  are 
most  commonly  changed  in  such  a way  as  appears  best  adapted  to 
the  form  of  the  animal.  The  change  in  the  habits  of  the  parent 
animal  arise  principally  from  its  connection  w’ith  the  human  kind, 
which  has  now  succeeded  in  training  dogs  so  as  to  fit  them,  both 
in  body  and  mind,  for  almost  every  purpose  of  human  oeconomy,  as 
if  man  iiirnself  had  formed  them  expressly  with  such  intention, 
while  at  the  same  time  he  can  only  be  considered  as  an  occasional 
cause,  for  we  may  observe  that  all  the  males  of  the  w’olf  kind  are 
nearly  the  same,  and  so  are  likewise  those  of  the  jackal,  having 
little  or  no  variety  in  their  dispositions.  Those  of  the  half-breed, 
and  even  those  that  are  three  removes,  although  tame,  yet  have  not 
the  docility  of  dogs,  nor  are  they  so  immediately  at  the  command 
of  the  human  will ; neither  are  they  perfectly  satisfied  with  an  arti- 
ficial life,  having  when  left  to  themselves  a propensity  to  fall  back 
into  their  original  instinctive  principles.* 

■ * [The  range  of  deviation  from  the  original  type  appears  to  be  greater  in  the 

dog  than  in  any  other  known  species.  Besides  the  well  known  and  considerable 
differences  in  the  quantity,  colour,  and  texture  of  the  hair,  and  in  the  size,  form, 
and  proportions  of  the  body,  in  some  individuals  an  additional  false  grinder  ap- 
pears; and  there  is  a race  of  dogs  which  have  a supernumerary  toe  on  the  hind- 
foot,  with  the  corresponding  tarsal  bones  — a variety  analogous  to  the  Dorking 
(or  five-toed)  fowl,  and  to  the  six-fingered  families  of  the  human  race.] 


[Cuv.  Disc.  Prelim.  Ossern.  Fossiles,  Ed.  iv.  tom.  i.,  p.  205.] 


OF  THE  WOLF,  JACKAL,  AND  DOG. 


833 


The  following  account  from  Mr.  Jenner,  of  Berkeley,  to  whom  I 
gave  a second  remove,  viz.,  three  parts  dog,  is  very  descriptive  of 
this  propensity : 

“The  little  jackal-bitch  you  gave  me  is  grown  a fine  handsome 
animal ; but  she  certainly  does  not  possess  the  understanding  of 
common  dogs.  She  is  easily  lost  when  I take  her  out,  and  is  quite 
inattentive  to  a whistle.  She  is  more  shy  than  a dog,  and  starts 
frequently  when  a quick  motion  is  made  before  her.  Of  her  inches 
she  is  uncommonly  fleet,  much  more  so  than  any  dog  I ever  saw. 
She  can  turn  a rabbit  in  the  field  ; she  is  fond  of  stealing  away 
and  lying  about  the  adjacent  meadows,  where  her  favourite  amuse- 
ment is  hunting  the  field-mouse,  which  she  catches  in  a particular 
manner.” 

As  animals  are  known  to  produce  young  which  are  different 
from  themselves  in  colour,  form,  and  dispositions,  arising  from 
what  may  be  called  the  unnatural  mode  of  life,  it  shows  this  curious 
power  of  accommodation  in  the  animal  oeconomy,  that  although 
education  can  produce  no  change  in  the  colour,  form,  or  disposition 
of  the  animal,  yet  it  is  capable  of  producing  a principle  which 
becomes  so  natural  to  the  animal  that  it'  shall  beget  young  different 
in  colour*  and  form,  and  so  altered  in  disposition  as  to  be  more 
easily  trained  up  to  the  offices  in  which  they  have  been  usually 
employed,  and  having  these  dispositions  suitable  to  such  change  of 
form. 

It  also  becomes  a question,  whether  they  would  not  go  back 
again  to  their  original  state,  if  put  into  the  situation  of  the  original 
from  whence  they  sprang;  or  acquire  a form  resembling  the  ori- 
ginal of  that  country  where  they  are  placed.  I do  not  conceive 
that  they  must  necessarily  go  back  through  the  same  changes;  but 
I have  some  reason  to  suppose  they  would  gradually  return  to  a 
resemblance  of  that  original.f  And  it  would  be  difficult  to  prove 
whether,  in  many  of  the  gradations,  they  are  progressive  or  retro- 
grade. But  this  is  a subject  that  requires  particular  attention  and 
investigation,  and  upon  which,  I hope,  some  time  or  other,  to  be 
able  to  throw  more  light. 

* [This  has  recently  been  exemplified  in  the  produce  of  a male  and  female 
Dingo,  or  wild  dog  of  Australia,  brought  forth  at  the  Zoological  Gardens,  and 
under  circumstances  which  precluded  the  possibility  of  connection  between  the 
female  and  any  other  dog  than  the  male  with  which  she  was  kept  confined.  Two, 
out  of  the  litter  of  five  puppies  brought  forth,  had  the  uniform  red-brown  colour 
of  the  parents,  the  rest  were  more  or  less  pied,  brown  and  white.] 

f [If  the  wolf  were  actually  the  original  of  the  dog,  it  might  have  been  expected 
that  the  Dingo  of  Australia,  supposing  it  to  have  originated  from  some  dog  ac- 
cidentally introduced  into  that  continent,  would  have  been  found  reverted  to  its 
original  condition,  or  as  a wolf.  But  there  appears  to  have  been  no  further  pro- 
gress towards  the  acquisition  of  the  characters  of  the  wolf,  in  this  instance,  than 
may  be  supposed,  on  the  theory  of  reversion,  to  have  taken  place  in  the  time  of 
Cook.  The  existence  of  wild  dogs  which  are  not  wolves,  as  the  Dingo  of  Aus- 
tralia and  the  Dhole  of  India,  which  have  either  lost  or  have  never  acquired  the 
common  character  of  domestication,  variety  of  colour,  is  itself  a strong  argument 
against  the  original  of  the  domestic  dog  ever  having  been  a wolf.] 


334 


HUNTER  ON  THE  ANIMAL  CBCONOMY, 


33.  OBSERVATIONS  ON  THE  STRUCTURE  AND  CECO- 
NOMY  OF  WHALES.  BY  JOHN  HUNTER,  ESQ.,  F.R.S.^ 

The  animals  which  inhabit  the  sea  are  much  less  known  to  us 
than  those  found  upon  land  ; and  the  osconomy  of  those  with  which 
we  are  best  acquainted  is  much  less  understood;  we  are,  therefore, 
too  often  obliged  to  reason  from  analogy  where  information  fails, 
which  must  probably  ever  continue  to  be  the  case,  from  our  unfit- 
ness to  pursue  our  researches  in  the  unfathomable  waters. 

This  unfitness  does  not  arise  from  that  part  of  our  oeconomy  on 
which  life  and  its  functions  depend,  for  the  tribe  of  animals  which 
is  to  be  the  subject  of  this  Paper  has,  in  that  respect,  the  same 
oeconomy  as  man,  but  from  a difierence  in  the  mechanism  by  which 
our  progressive  motion  is  produced. 

The  anatomy  of  the  larger  marine  animals,  when  they  are 
procured  in  a proper  state,  can  be  as  well  ascertained  as  that  of 
any  others,  dead  structure  being  readily  investigated.  But  even 
such  opportunities  too  seldom  occur,  because  those  animals  are 
only  to  be  found  in  distant  seas,  which  no  one  explores  in  pursuit 
of  natural  history ; neither  can  they  be  brought  to  us  alive  from 
thence,  which  prevents  our  receiving  their  bodies  in  a state  fit  for 
dissection.  As  they  cannot  live  in  air,  we  are  unable  to  procure 
them  alive. 

Some  of  these  aquatic  animals  yielding  substances  which  have 
become  articles  of  traffic,  and  in  quantity  sufficient  to  render  them 
valuable  as  objects  of  profit,  are  sought  after  for  that  purpose  ; but 
gain  being  the  primary  view,  the  researches  of  the  Naturalist  are 
only  considered  as  secondary  points,  if  considered  at  all.  At  the 
best  our  opportunities  of  examining  such  animals  do  not  often  occur 
till  the  parts  are  in  such  a state  as  to  defeat  the  purposes  of  accurate 
inquiry,  and  even  these  occasions  are  so  rare  as  to  prevent  our 
being  able  to  supply,  by  a second  dissection,  what  was  deficient  in 
a first.  The  parts  of  such  animals  being  formed  on  so  large  a 
scale,  is  another  cause  which  prevents  any  great  degree  of  accuracy 
in  their  examination,  more  especially  when  it  is  considered  how  very 
inconvenient  for  accurate  dissections  are  barges,  open  fields,  and 
such  places  as  are  fit  to  receive  animals  or  parts  of  such  vast 
bulk. 

As  the  opportunities  of  ascertaining  the  anatomical  structure  of 
large  marine  animals  are  generally  accidental,  I have  availed 
myself  as  much  as  possible  of  all  that  have  occurred  ; and,  anxious 
to  get  more  extensive  information,  engaged  a surgeon,  at  a con- 
siderable expense,  to  make  a voyage  to  Greenland,  in  one  of  the 
ships  employed  in  the  whale  fishery,  and  furnished  him  with  such 
necessaries  as  I thought  might  be  requisite  for  examining  and  pre. 

* [Originally  published  in  the  Philosophical  Transactions,  vol.  Ixxvii.  1787.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC, 


335 


serving  the  more  interesting  parts,  and  with  instructions  for 
making  general  observations ; but  the  only  return  I received  for 
this  expense  was  a piece  of  whale’s  skin,  with  some  small  animals 
sticking  upon  it.  From  the  opportunities  which  I have  had  of 
examining  different  animals  of  this  order,  I have  gained  a tolera- 
bly accurate  idea  of  the  anatomical  structure  of  some  genera,  and 
such  a knowledge  of  the  structure  of  particular  parts  of  some 
others,  as  to  enable  me  to  ascertain  the  principles  of  their 
oeconomy, 

Those  which  I have  had  opportunities  of  examining  were  the 
following : 

Of  the  Delphinus  Phoccena,  or  Porpoise,  I have  had  several,  both 
male  and  female. 

Of  the  Grampus  I have  had  two;  one  of  them,  {Delphinus 
Orca,  Linn.  Tab.  XLIV.)  twenty-four  feet  long,  the  belly  of  a 
white  colour,  which  terminated  at  once,  the  sides  and  back  being 
black;  the  other  about  eighteen  feet  long,  the  belly  white,  but  less 
so  than  in  the  former,  and  shaded  off  into  the  dark  colour  of  the 
back. 

Of  the  Delphinus  Delphis,  or  Bottle-nose  whale  (Tab.  XLVI.),  I 
had  one  sent  to  me  by  Mr.  Jenner,  surgeon,  at  Berkeley.  It  was 
about  eleven  feet  long. 

I have  also  had  one  twenty-one  feet  long,  resembling  this  last  in 
the  shape  of  the  head,  but  of  a different  genus,  having  only  two  teeth 
in  the  lower  jaw  (Tab.  XLVII.);  the  belly  was  white,  shaded  off 
into  the  dark  colour  of  the  back.  This  species  is  described  by 
Dale  in  his  Antiquities  of  Harwich.  The  one  which  I examined 
must  have  been  young,  for  I have  a skull  of  the  same  kind  nearly 
three  times  as  large,  which  must  have  belonged  to  an  animal  thirty 
or  forty  feet  long. 

Of  the  Balcena  rostrata  of  Fabricius  I had  one  seventeen  feet  long. 
(Tab.  XLVIII.) 

The  Balcena  Mysticetus,  or  large  Whalebone  whale,  the  Physeter 
JUacrocephalus,  or  Spermaceti  whale,  and  the  Monoclon  JMonoceros, 
or  Nar-whale,  have  also  fallen  under  my  inspection.  Some  of  these 
I have  had  opportunities  of  examining  with  accuracy,  while  others 
I have  only  examined  in  part,  the  animals  having  been  too  long 
kept  before  I procured  them  to  admit  of  more  than  a very  superficial 
inspection.* 

* [Cuvier,  in  his  masterly  Chapter  on  existing  Cetaceans  (Ossem.  Foss.,  tom. 
V.  pt.  i.),  divides  the  Ba/aense  or  true  whales,  (cetaceans  having  the  roof  of  the 
mouth  furnished  with  baleen  or  whalebone),  into  those  which  have,  and  those 
which  have  not  a dorsal  fin.  Of  the  latter  he  admits  but  one  species,  frequenting 
the  northern  latitudes,  to  be  accurately  defined,  viz.,  the  Balsena  Mysticetus  of 
Linnseus,  and  which  Hunter,  from  the  relative  size  of  its  baleen-plates  terms  the 
‘ large  whalebone  whale.’  The  species  M Balxna  found  in  the  southern  latitude 
differs,  according  to  Cuvier,  from  the  Bal.  Mysticetus,  in  having  all  its  cervical 
vertebrae  anchylosed,  while  in  Bal.  Mysticetus  the  five  posterior  cervical  vertebrae 
remain  detached;  and  in  the  number  of  ribs,  which  are  thirteen  pairs  in  the 


336 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


From  these  circumstances  it  will  be  readily  supposed  that  an 
accurate  description  of  all  the  difl’erent  species  is  not  to  he  ex- 
pected ; but  having  acquired  a general  knowledge  of  the  whole 

Bal.  Mys/icehis,  and  fifteen  in  \\\b  Bal.  Auslralin : there  are  also  well-marked 
differences  in  the  form  of  the  skull  in  the  two  species. 

Of  the  fin-backed  wliales  or  Balsnnpterse,  Cuvier  considers  the  existence  of 
the  species  without  ventral  plicre,  called  gibbar  or  finfish,  as  reposing  on  more 
than  doubtful  authority  : in  the  original  figure  by  Martens  {^Voyage  dii  Spitzberg, 
1G71),  Cuvier  supposes  that  the  plicte  were  accidentally  omitted,  rather  than 
absent  in  nature,  since  lie  finds  that  the  skull  of  the  so  called  gibbar,  figured  by 
Camper,  and  its  skeleton  figured  by  Albers  {leones  ad  Anat,,  Comp,  illusti’.),  are 
identical  with  those  of  the  liurquuls  or  Balxnoptera:  with  the  skin  of  the  throat  and 
fore  part  of  the  abdomen  disposed  in  longitudinal  folds.  Mr.  Hunter  had  evi- 
dently never  met  with  a specimen  of  the  supposed  gibbar,  and,  as  he  derived  his 
observations  from  Nature  alone,  he  did  not  contribute  towards  perpetuating  the 
error  of  Martens,  as  most  nomenclative  naturalists  and  compilers  had  done  up  to 
his  time,  and  continued  to  do  until  the  publication  of  the  works  of  Scoresby  and 
Cuvier. 

The  principal  characters  by  which  the  Rorquals  {Balsenoplerai)  differ  from  the 
Balsenee,?ixe  the  greater  flatness  of  the  head,  the  lower  jaw  projecting  beyond  the 
upper,  the  skin  under  the  throat,  chest,  and  anterior  part  of  the  abdomen  longitu- 
dinally plicated  and  dilatable  ; the  short  and  hard  baleen-plates,  terminating 
in  stiff  and  brittle  bristles,  a short  and  thick  fin  on  the  hinder  region  of  the 
back. 

Of  the  Balsenopterse  which  frequent  the  northern  latitudes  three  species  have 
been  admitted  into  the  Zoologists'  Catalogues,  Balxnnptera  Bonps,  Bal.  musculus, 
Bal.  roslrata.  Cuvier  submits  these  species  to  a criticism,  severe,  as  usual,  but 
just;  he  finds  that  no  two  of  the  species  have  ever  been  compared  or  seen  by 
one  naturalist,  either  together  or  at  different  periods  : that  the  only  appreciable 
differences  he  can  gather  from  the  best  of  their  accounts  resolve  themselves  into 
those  of  size  or  degrees  of  mutilation  of  the  dorsal  fin  : and  hs  asks,  “ Qui  oseroit, 
d’apres  I’observation  d’individus  vus  isolement  a de  grandes  distances  de  temps 
et  de  lieux,  et  par  de  personnes  diverses,  soulenir  que  ces  differences  ne  venoient 
pas  de  Page  I”  Fabricius,  however,  assigns  three  rows  of  low  ridges  on  the 
upper  part  of  the  head,  extending  forwards  from  the  blow-holes,  as  a character 
distinguishing  his  /?oops  from  Balxna  rostrata : a.  moxe  important  dis- 

tinction is  afforded  by  the  number  of  vertebrae. 

The  Bal.  musculus  attains,  according  to  Scoresby,  the  length  of  seventy  or 
eighty  feet  ; the  Bal,  Boups  of  the  same  author  that  of  forty-six  feet.  The  Bal. 
roslrata  of  Fabricius  is  variously  described  as  seventeen,  twenty,  and  twenty- 
five  feet  in  length. 

The  young  Rorqual  dissected  by  Hunter  was  but  seventeen  feet  long,  and  he 
accordingly  refers  it  to  the  Bal.  roslrata  of  Fabricius.  In  speaking  of  it  he 
generally  uses  the  term  applied  by  Sibbald  to  the  species  of  which  this  is  sup- 
jiosed  by  Cuvier  to  be  the  young,  viz.,  whale;’  and  sometimes  from  the 

relative  size  of  the  baleen  plates,  calls  it  ‘small  whalebone  whale,’  in  contradis- 
tinction to  the  ‘large  whalebone  whale,’  or  Balxna  mysticctus  ; not  referring  to 
the  relative  difference  in  the  general  bulk  of  the  body,  in  which  the  ‘ small  whale- 
bone whale’  {Balxnoptera  Boops,  Cuv.)  has  the  advantage,  since  it  attains  the 
length  of  from  eighty  to  one  hundred  feet,  while  the  ‘ large  whalebone  whale’ 
was  never  seen  by  Scoresby  to  exceed  the  length  of  sixty  feet,  nor  was  ever  re- 
ported to  him  to  have  been  longer  than  sixty-seven  feet. 

The  whale  described  by  Dale,  in  Taylor’s  Antiquities  of  Harwich  (p.  411, 
pi.  xiv.),  of  which  species  Hunter  dissected  an  individual,  twenty-one  feet  in 
length,  is  generally  called  by  him  the  ‘ great  bottle-nose  whale,’  in  contradistinc- 
tion to  the  Delphinus  tursio,  which  he  calls  also  ‘bottle-nose,’  or  ‘small  bottle- 
nose  whale.’  Dale’s  whale  is  distinguished  chiefly  by  the  presence  of  only  two 
small  teeth  in  the  lower  jaw,  and  a number  of  horny  tooth-like  projections  from 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


337 


tribe  from  the  difierent  species  which  have  come  under  my  ex- 
amination, I have  been  enabled  to  form  a tolerable  idea,  even  of 
parts  which  I have  only  had  the  opportunity  of  seeing  in  a very 
cursory  way. 

General  observation  would  lead  us  to  believe  that  the  whole  of 
this  tribe  constitutes  one  order  of  animals,  which  naturalists  have 
subdivided  into  genera  and  species ; but  a deficiency  in  the 
knowledge  of  their  oeconomy  has  prevented  them  from  making 
these  divisions  with  sufficient  accuracy  ; and  this  is  not  surprising, 
since  the  genera  and  species  are  still  in  some  measure  undeter- 
mined, even  in  animals  with  which  we  are  better  acquainted. 

The  animals  of  this  order  are  in  size  the  largest  known,  and 
probably,  therefore,  the  fewest  in  number  of  all  that  live  in  water. 
Size,  I believe,  in  those  animals  which  feed  upon  others,  is  in  an 
inverse  proportion  to  the  number  of  the  smaller  ; but  I believe  this 
tribe  varies  more  in  that  I'espect  than  any  we  know,  viewing  it 
from  the  whalebone  whale,  which  is  seventy  or  eighty  feet  long,* 
to  the  porpoise,  that  is  five  or  six:  however,  if  they  differ  as  much 
among  themselves  as  the  salmon  does  from  the  sprat,  there  is  not 
that  comparative  difference  in  size  that  would  at  first  appear.  The 
whalebone  whale  is,  I believe,  the  largest ; the  spermaceti  whale 
the  next  in  size  (the  one  which  I examined,  although  not  full 
grown,  was  about  sixty  feet  long);  the  grampus,  which  is  an  exten- 
sive genus,  is  probably  from  twenty  to  fifty  feet  long;  under  this 
denomination  there  is  a number  of  species. 

the  roof  of  the  mouth,  which  Cuvier  conjectures  may  be  the  rudiments  or  ana- 
logues of  the  baleen  of  the  true  whales.  This  Cetacean  is  now  considered  the 
type  of  a new  genus,  called  by  Lacepede  ‘ Hyperoodun'  and  the  only  well-ascer- 
tained species  is  generally  designated,  after  its  original  describer,  Dale,  ^ Hype- 
roodon  Bald.'  The  individual  described  by  Dale  was  fourteen  feet  in  length. 
Another  described  by  Chemnitz,  which  was  captured  at  Spitzbergen,  m.easured 
twenty-five  feet.  A female,  which  was  taken  with  her  young  one,  near  Harfleur, 
in  1788,  was  twenty-three  feet  in  length.  Nevertheless,  the  skeleton  of  the 
Hunterian  specimen  manifests  all  the  characters  of  immature  age,  in  the  separation 
of  the  epiphyses  ; although  it  is  to  be  observed  that  these  parts  are  anchylosed 
less  early  in  the  Cetacea  than  in  the  land  m.ammalia. 

The  small  bottle-nose  whale  of  Hunter,  is  not  the  common  dolphin,  Delphinus 
delphis,  L.,  as  he  supposed,  but  the  Bdphinus  Tursio  of  Fabricius,  as  is  shown 
by  the  skull  and  other  parts  which  are  preserved  in  the  Hunterian  Collection,  as 
well  as  by  the  size  of  the  specimen  which  Hunter  describes.  The  Belphinus 
delphis  is  from  six  to  seven  feet  in  length,  and  has  from  forty-two  to  forty-seven 
teeth  on  each  side  of  each  jaw.  The  Belphinus  Tursio  attains  the  length  of  ten 
and  eleven  feet,  and  has  from  twenty-one  to  twenty-three  teeth  on  each  side  of 
each  jaw  ; which  teeth  are  conical,  but  proportionallj' larger  and  more  obtuse 
than  in  B.  delphis.^ 

* [This,  as  an  average  size,  can  only  be  attributed  to  the  largest  of  the  Ba/ss- 
nopterae  or  fin-backed  whales.  The  usual  length  of  the  largest  cachalots  (^Physeler 
macrocephalus,  Shaw,)  taken  in  the  South  Seas  is  about  sixty-feet;  but  this  size 
refers  only  to  the  males,  for  there  is  a remarkable  disproportion  in  the  size  of  the 
two  sexes  in  this  species  of  Cetacean,  the  full-grown  female  of  which  rarely^ 
exceeds  thirty-five  feet.  The  difference  is  principally  in  the  length  of  the  jaws, 
which  are  twice  as  long  in  the  male  as  in  the  female,  reminding  one  of  the  sexual 
characters  afforded  by  the  mandibles  in  the  Lucani  or  stag-beetles,] 

30 


338 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


From  my  want  of  knowledge  of  the  different  genera  of  this  tribe 
of  animals,  an  incorrectness  in  the  application  of  the  anatomical 
account  to  the  proper  genus  may  be  the  consequence ; for  when 
they  are  of  a certain  size  they  are  brought  to  us  as  porpoises; 
when  larger  they  are  called  grampus  or  fin-fish.  A tolerably  cor- 
rect anatomical  description  of  each  species,  with  an  accurate 
drawing  of  the  external  form,  would  lead  us  to  a knowledge  of  the 
different  genera,  and  the  species  in  each  ; and,  in  order  to  forward 
so  useful  a work,  I propose,  at  some  future  period,  to  lay  before  the 
Society  descriptions  and  drawings  of  those  which  have  come  under 
my  own  observation. 

From  some  circumstances  in  their  digestive  m'gans  we  should 
be  led  to  suppose  that  they  were  nearly  allied  to  each  other,  and 
that  there  was  not  the  same  variety  in  this  respect  as  in  land 
animals. 

In  the  description  of  this  order  of  animals  I shall  always  keep  in 
view  their  analogy  to  land  animals,  and  to  such  as  occasionally 
inhabit  the  water,  as  white  bears,  seals,  manatees,*  &c.,  with  the 
differences  that  occur.  This  mode  of  referring  them  to  other 
animals  better  known  will  assist  the  mind  in  understanding  the  pre- 
sent subject.  It  is  not,  however,  intended  in  this  paper  to  give  a 
particular  account  of  the  structure  of  all  the  animals  of  this  order 
which  I have  had  an  opportunity  of  examining  : I propose  at  pre- 
sent chiefly  to  confine  myself  to  general  principles,  giving  the  great 
outlines  as  far  as  I am  acquainted  with  them,  minuteness  being 
only  necessary  in  the  investigation  of  particular  parts. 

In  my  account  I shall  pay  some  attention  to  the  relations  of  men 
who  have  given  facts  without  knowing  their  causes,  whenever  I 
find  that  such  facts  can  be  explained  upon  true  principles  of  the 
animal  ceconomy,  but  no  further. 

This  order  of  animals  has  nothing  peculiar  to  fish,  except  living 
in  the  same  element,  and  being  endowed  with  the  same  powers  of 
progressive  motion  as  those  fish  that  are  intended  to  move  with  a 
considerable  velocity;  for  I believe  that  all  that  come  to  the  sur- 
face of  the  water  (which  this  order  of  animals  must  do)  have  con- 
siderable progressive  motion  ; and  this  reasoning  we  may  apply 
to  birds,  for  those  which  soar  very  high  have  the  greatest  pro- 
gressive motion. 

Although  inhabitants  of  the  waters  they  belong  to  the  same 
class  as  quadrupeds,  breathing  air,  being  furnished  with  lungs  and 
all  the  other  parts  peculiar  to  the  ceconomy  of  that  class,  and 
having  warm  blood  ; for  we  make  this  general  remark,  that  in  the 
different  classes  of  animals  there  is  never  any  mixture  of  those 

* [The  aquatic  mammalia  which  Hunter  includes  under  this  name  are  associated 
by  Cuvier,  in  consequence  of  the  absence  of  hinder  extremities,  with  the  true 
Cetacea.  Tiiey  include  the  manatee  of  South  America  (^Manatus),  the  diigong 
of  the  Indian  Ocean  and  Red  Sea  {^Halicore),  and  the  manatee  of  the  Arctic  Seas 
(liytina).  They  are  all  herbivorous,  and  differ  in  many  anatomical  particulars 
irom  the  true  cetacea,  which  are  the  subjects  of  Hunter’s  observations;  connect- 
ing these  mammalia  with  the  quadrupeds  of  the  Pachydermatous  order,] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC, 


339 


parts  which  are  essential  to  life,  nor  in  their  different  mode  of 
sensation.* 

I shall  divide  what  is  called  the  osconomy  of  an  animal : 

First,  into  those  parts  and  actions  which  respect  its  internal 
functions,  and  on  which  life  immediately  depends,  as  growth,  waste, 
repair,  shifting  or  changing  of  parts,  &c.,  the  organs  of  respiration 
and  secretion,  in  w-hich  we  may  include  the  powers  of  propagating 
the  species. 

Secondly,  into  those  parts  and  actions  which  respect  external 
objects,  and  which  are  variously  constructed,  according  to  the 
kind  of  matter  with  which  they  are  to  be  connected,  whence  they 
vary  more  than  those  of  the  first  division.  These  are  the  parts 
for  progressive  motion,  the  organs  of  sense  and  the  organs  of  diges- 
tion ; all  of  which  either  act  upon,  or  are  acted  upon,  by  external 
matter. 

This  variation  from  external  causes  in  many  instances  influences 
the  shape  of  the  whole,  or  particular  parts,  even  giving  a peculiar 
form  to  some  parts  which  belong  to  the  first  order  of  actions,  as 
the  heart,  which  in  this  tribe,  in  the  seal,  otter,  &c.,  is  flattened 
because  the  chest  is  flattened  for  the  purpose  of  swimming.  The 
contents  of  the  abdomen  are  not  only  adapted  to  the  external 
form;  but  their  direction  in  the  cavity  is,  in  some  instances,  regu- 
lated by  it.  The  anterior  extremities,  or  fins,  although  formed  of 
distinct  parts,  in  some  degree  similar  to  the  anterior  extremities  of 
some  quadrupeds,  being  composed  of  similar  bones  placed  nearly 
in  the  same  manner,  yet  are  so  formed  and  arranged  as  to  fit  them 
for  progressive  motion  in  the  water  only. 

The  external  form  of  this  order  of  animals  is  such  as  fits  them 
for  dividing  the  water  in  progressive  motion,  and  gives  them  powder 
to  produce  that  motion  in  the  same  manner  as  those  fish  which 
move  with  a considerable  velocity.  On  account  of  their  inhabiting 
the  water,  their  external  form  is  more  uniform  than  in  animals  of 
the  same  class  which  live  upon  land ; the  surface  of  the  earthen 
which  the  progressive  motion  of  the  quadruped  is  to  be  performed 
being  various  and  irregular,  while  the  water  is  always  the  same. 

The  form  of  the  head  or  anterior  part  of  this  order  of  animals  is 
commonly  a cone,  or  an  inclined  plane,  except  in  the  spermaceti 
whale,  in  which  it  terminates  in  a blunt  surface.  This  form  of  head 
increases  the  surface  of  contact  to  the  same  volume  of  water  which 
it  removes,  lessens  the  pressure,  and  is  better  calculated  to  bear  the 
resistance  of  the  water  through  which  the  animal  is  to  pass ; probably 
on  this  account  the  head  is  larger  than  in  quadrupeds,  having  more 
the  proportion  observed  in  fish,  and  swelling  out  laterally  at  the 

* [That  is,  there  is  never  any  combination  of  the  modifications  of  vital  organs 
characteristic  of  two  different  classes  of  animals  in  the  same  species,  as  of  a 
double  heart  of  the  mammal  with  the  branchioe  of  a fish  ; nor  is  the  structure  of 
the  organ  of  hearing,  or  of  any  other  sense  characteristic  of  a higher  class  of 
vertebrata,  ever  combined  with  a modification  of  the  vital  organs  peculiar  to  a 
lower  class.] 


340 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


articulation  of  the  lower  jaw.  This  may  probably  be  for  the  better 
catching  their  prey,  as  they  have  no  motion  of  the  head  on  the  body, 
and  this  distance  between  the  articulations  of  the  jaw  is  somewhat 
similar  to  the  swallow,  goat-sucker,  bat,  &c.,  which  may  also  be 
accounted  for  from  their  catching  their  food  in  the  same  rtianner 
as  fish  ; and  this  is  rendered  still  more  probable,  since  tbc  form  of 
the  mouth  varies  according  as  they  have  or  have  not  teeth.  There 
is,  however,  in  the  whale  tribe  more  variety  in  the  form  of  the  head 
than  of  any  other  part,  as  in  the  whalebone,  bottle-nose,  and  sper- 
maceti whales ; though  in  this  last  it  appears  to  owe  its  shape  in 
some  sort  to  the  vast  quantity  of  spermaceti  lodged  there,  and  not 
to  be  formed  merely  for  the  catching  of  its  prey.  From  the  mode 
of  their  progressive  motion  they  have  not  the  connexion  between 
the  head  and  body  that  is  called  the  neck,  as  that  would  have  pro- 
duced an  inequality  inconvenient  to  progressive  motion. 

The  body  behind  the  fins  or  shoulders  diminishes  gradually  to  the 
spreading  of  the  tail ; but  the  part  beyond  the  opening  of  the  anus  is 
to  be  considered  as  tail,  although  to  appearance  it  is  a continuation 
of  the  body.  The  body  itself  is  flattened  laterally,  and  I believe  the 
back  is  much  sharper  than  the  belly. 

The  projecting  part,  or  tail,  contains  the  power  that  produces 
progressive  motion  and  moves  the  broad  termination,  the  motion 
of  which  is  similar  to  that  of  an  oar  in  sculling  a boat ; it  supersedes 
the  necessity  of  posterior  extremities,  and  allows  of  the  proper  shape 
for  swimming.  That  the  form  may  be  preserved  as  much  as  pos- 
sible, we  find  that  all  the  projecting  parts  found  in  land  animals  of 
the  same  class  are  either  entirely  wanting,  as  the  external  ear;  are 
placed  internally,  as  the  testicles  ; or  are  spread  along  under  the 
skin,  as  the  udder. 

The  tail  is  flattened  horizontally,  which  is  contrary  to  that  fish,* 
this  position  of  tail  giving  the  direction  to  the  animal  in  the  pro- 
gressive motion  of  the  body.  I shall  not  pursue  this  circumstance 
further  than  to  apply  it  to  those  purposes  in  the  animal  ceconomy 
for  which  this  particular  direction  is  intended. 

The  tw’O  lateral  fins,  which  are  analogous  to  the  anterior  ex- 
tremities in  the  quadruped,  are  commonly  small,  varying  however 
in  size,  and  seem  to  serve  as  a kind  of  oars. 

To  ascertain  the  use  of  the  fin  on  the  back  is  probably  not  so 
easy,  as  the  large  whalebone  and  spermaceti  whales  have  it  not  ; 
one  should  otherwise  conceive  it  is  intended  to  preserve  the  animal 
from  turning. 

I believe,  like  most  animals,  they  are  of  a lighter  colour  on  their 

* [This  difference  in  the  position  of  the  tail-fin  relates  chiefly  to  the  difference 
between  the  whale  and  fish  in  the  mode  and  amount  of  respiration;  the  warm- 
blooded whale  requiring  a frequent  ascent  to  the  surface  of  the  water  to  breathe 
the  air,  which  the  horizontal  tail  enables  it  to  do.  In  the  air-breathing  Ichthyo- 
saurus, the  presence  of  a pair  of  horizontal  flattened  posterior  paddles,  for  direct- 
ing the  snout  to  the  surface  of  the  water,  enabled  that  extinct  reptile  to  have  lungs 
in  combination  with  the  vertical  tail  of  the  fish.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


341 


belly  than  on  their  back ; in  some  they  are  entirely  white  on  the 
belly,  and  this  white  colour  begins  by  a regular  determined  line,  as 
in  the  grampus,  piked  whale,  &c. ; in  others,  the  white  on  the  belly 
is  gradually  shaded  into  the  dark  colour  of  the  back,  as  in  the  por- 
poise. I have  been  informed  that  some  of  them  are  pied  upwards 
and  downwards,*  or  have  the  divisions  of  colour  in  a contrary 
direction. 

The  element  in  which  they  live  renders  certain  parts  which  are 
of  importance  in  other  animals  useless  in  them,  gives  to  some  parts 
a diflerent  action,  and  renders  others  of  less  account. 

The  puncta  lachrymalia  with  the  appendages,  as  the  sac  and 
duct,  are  in  them  unnecessary  ; and  the  secretion  from  the  lachry- 
mal gland  is  not  water,  but  mucus,  as  it  also  is  in  the  turtle  ; and 
we  may  suppose  only  in  small  quantity,  the  gland  itself  being  small. 

The  urinary  bladder  is  smaller  than  in  quadrupeds,  and  indeed 
there  is  not  any  apparent  reason  why  whales  should  have  one  at  all. 

The  tongue  is  flat  and  but  little  projecting,  as  they  neither  have 
• voice  nor  require  much  action  of  this  part,  in  applying  the  food  be- 
tween the  teeth  for  the  purpose  of  mastication  or  deglutition,  being 
nearly  similar  to  fish  in  this  respect  as  well  as  in  their  progressive 
motion. 

In  some  particulars  they  differ  as  much  from  one  another  as  any 
two  genera  of  quadrupeds  I am  acquainted  with. 

The  larynx,  size  of  trachea,  and  number  of  ribs  differ  exceedingly 
The  cEecum  is  only  found  in  some  of  them.  The  teeth  in  some  are 
wanting.  The  blow-holes  are  two  in  number  in  many,  in  others 
only  one.  The  whalebone  and  spermaceti  are  peculiar  to  particular 
genera  ; all  which  constitute  great  variations.  In  other  respects 
we  find  an  uniformity,  which  would  appear  to  be  independent  of 
their  living  and  moving  only  in  the  water,  as  in  the  stomach,  liver, 
parts  of  generation  of  both  sexes,  and  in  the  kidneys.  In  these  last, 
however,  I believe  it  depends  in  some  degree  upon  their  situation, 
although  it  is  extended  to  other  animals,  the  cause  of  which  I do 
not  understand. 

All  animals  have,  I believe,  a smell  peculiar  to  the.mselves;  how 
far  this  is  connected  with  the  other  distinctions  I do  not  know,  our 
organs  not  being  able  to  distinguish  with  sufficient  accuracy. 

The  smell  of  animals  of  this  tribe  is  the  same  with  that  of  the 
seal,  but  not  so  strong,  a kind  of  sour  smell,  wdffch  the  seal  has 
while  alive;  the  oil  has  the  same  smell  with  that  of  the  salmon, 
herring,  sprat,  &c. 

The  observations  respecting  the  weight  of  the  flesh  of  animals 
that  swim,  which  I published  in  my  Observations  on  the  (Economy 
of  certain  parts  of  Animals,*  ai’e  applicable  to  these  also  ; for  the 
ffoeh  in  this  tribe  is  rather  heavier  than  beef ; two  portions  of  mus- 
cle of  the  same  shape,  one  from  the  psoas  muscle  of  the  whale,  the 

* [This  irregular  distribution  of  the  dark  and  light  shades  is  remarkable  in  the 
Phocxna  Rissoana  of  Fred.  Cuvier.] 

t [Pages  200,  281.] 

30* 


342 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Other  of  an  ox,  when  weighed  in  air,  were  both  exactly  502  grains  ; 
but  weighed  in  water,  the  portion  of  the  whale  was  four  grains 
heavier  than  the  other.  It  is  probable,  therefore,  that  the  necessary 
equilibrium  between  the  water  and  the  animal  is  produced  by  the  oil, 
in  addition  to  which  the  principal  action  of  the  tail  is  such  as  tends 
either  to  raise  them  or  to  keep  them  suspended  in  the  water,  ac- 
cording to  the  degree  of  force  with  which  it  acts. 

From  the  tail  being  horizontal,  the  motion  of  the  animal,  when 
impelled  by  it,  is  up  and  down  ; two  advantages  are  gained  by  this, 
it  gives  the  necessary  opportunity  of  breathing,  and  elevates  them 
in  the  water  ; for  every  motion  of  the  tail  tends,  as  I said  before,  to 
raise  the  animal ; and  that  this  may  be  effected,  the  greatest  mo- 
tion of  the  tail  is  downwards,  those  muscles  being  very  large, 
making  two  ridges  in  the  abdomen;  this  motion  of  the  tail  raises 
the  anterior  extremity,  which  always  tends  to  keep  the  body  sus- 
pended in  the  water. 

Of  the  Bones. 

The  bones  alone,  in  many  animals,  when  properly  united  into 
what  is  called  the  skeleton,  give  the  general  shape  and  character 
of  the  animal.  Thus  a quadruped  is  distinguished  from  a bird,  and 
even  one  quadruped  from  another;  it  only  requiring  a skin  to  be 
thrown  over  the  skeleton  to  make  the  species  known.  But  this  is 
not  so  decidedly  the  case  with  this  order  of  animals,  for  the  skeleton 
in  them  does  not  give  us  the  true  shape.  An  immense  head,  a 
small  neck,  few  ribs,  and  in  many  a short  sternum  and  no  pelvis, 
with  a long  spine  terminating  in  a point,  require  more  than  a skin 
being  laid  over  them  to  give  the  regular  and  characteristic  form 
of  the  animal. 

The  bones  of  the  anterior  extremity  give  no  idea  of  the  shape  of 
a fin,  the  form  of  W'hich  depends  wholly  upon  its  covering.  The 
different  parts  of  the  skeleton  are  so  inclosed,  and  the  spaces  betw’een 
the  projecting  parts  are  so  filled  up,  as  to  be  altogether  concealed, 
giving  the  animal  externally  an  uniform  and  elegant  form,  resem- 
bling an  insect  enveloped  in  its  chrysalis  coat. 

The  bones  of  the  head  are  in  general  so  large  as  to  render  the 
ca\^ity  which  contains  the  brain  but  a small  part  of  the  whole  ; 
while  in  the  human  species  and  in  birds  this  cavity  constitutes  the 
principal  bulk  of  the  head.  This  is,  perhaps,  most  remarkable  in 
the  spermaceti  whale;  for,  on  a general  view  of  the  bones  of  the 
head,  it  is  impossible  to  determine  where  the  cavity  of  the  skull  lies 
till  led  to  it  by  the  foramen  magnum  occipitale.  The  same  remark 
is  applicable  to  the  large  whalebone  and  bottle-nose  whale;  but  in 
the  porpoise,  where  the  brain  is  larger  in  proportion  to  the  size  of 
the  animal,  the  skull  makes  the  principal  part  of  the  head. 

Some  of  the  bones  in  one  genus  differ  from  those  of  another. 
The  lower  jaw  is  an  instance  of  this.  In  the  spermaceti  and  bottle- 
nose  whales,  the  grampus,  and  the  porpoise,  the  lower  jaws,  espe- 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC, 


343 


cially  at  the  posterior  ends,  resemble  each  other ; but  in  both  the 
large  and  small  whalebone  whales  the  shape  differs  considerably. 
The  number  of  some  particular  bones  varies  likewise  very  much. 

The  piked  whale  has  seven  vertebrae  in  the  neck,  twelve  w'hich 
may  be  reckoned  to  the  back,  and  twenty-seven  to  the  tail,  making 
forty-six  in  the  whole.* 

In  the  porpoise  there  are  five  cervical  vertebrse,  and  one  common 
to  the  neck  and  back,  fourteen  proper  to  the  back,  and  thirty  to  the 
tail ; making  in  the  whole  fifty-one.f 

The  small  bottle-nose  whale,  caught  near  Berkeley,  in  the  number 
of  cervical  vertebrae  resembled  the  porpoise : it  had  seventeen  in 
the  back,  and  thirty-seven  in  the  tail ; in  all  sixty. J 

In  the  porpoise  four  of  the  vertebrae  of  the  neck  are  anchylosed  ; 
and  in  every  animal  of  this  order  which  I have  examined  the  atlas 
is  by  much  the  thickest,  and  seems  to  be  made  up  of  two  joined 
together,  for  the  second  cervical  nerve  passes  through  a foramen  in 
this  vertebra.  There  is  no  articulation  for  rotatory  motion  between 
the  first  and  second  v^ertebras  of  the  neck. 

The  small  bottle-nose  whale  had  eighteen  ribs  on  each  side,  the 
porpoise  sixteen. § The  ends  of  the  ribs  that  have  two  articulations, 
in  the  whole  of  this  tribe,  I believe,  are  articulated  with  the  body 
of  the  vertebrae  above  (or  before)  and  with  the  transverse  processes 
below  (or  of  the  succeeding  vertebra),  by  the  angles  ; so  that  there 
is  one  vertebra  common  to  the  neck  and  back.  In  the  large  whale- 
bone whale  the  first  rib  is  bifurcated,  and  consequently  articulated 
to  two  vertebras. 

The  sternum  is  very  flat  in  the  piked  whale,  it  is  only  one  very 
short  bone;  and  in  the  porpoise  it  is  a good  deal  longer.  In  the 
small  bottle-nose  it  is  composed  of  three  bones,  and  is  of  some 

* [In  the  skeleton  of  the  Balasna  rosfrata  preserved  in  the  Museum  of  the  College 
of  Surgeons,  there  are  only  eleven  pairs  cf  ribs,  and  two  or  three  vertebra  are 
wanting  at  the  extremity  of  the  tail ; but  the  total  number  of  vertebrae  could  not 
have  exceeded  fifty.  In  the  Balsenoptera  Boops  the  number  of  vertebrae  exceeds 
sixty  ; there  being  seven  cervical,  fourteen  dorsal,  and  from  forty-one  to  forty-four 
caudal  vertebrae.  In  the  skeleton  of  this  species,  exhibited  in  the  year  1827,  in 
London,  at  Charing-cross,  sixty-two  vertebrae  were  distinguishable,  and  two  or 
three  more  must  have  been  concealed  in  the  portion  of  the  tail  which  had  been 
preserved  in  tsiiu.  There  were  fourteen  pairs  of  ribs.  Cuvier,  in  the  second  edi- 
tion of  his  ‘ Le9ons  d’Anatoinie  Compares,’  assigns  sixty-five  vertebrae  to  the 
Balsmoptera  Boops,  of  which  fourteen  are  dorsal.  In  the  Balama  Mysticetus  there 
are  forty-eight  vertebrae,  viz.,  seven  cervical,  thirteen  dorsal,  and  twenty-eight 
caudal.] 

f [In  the  skeletons  which  we  have  examined  there  are  seven  cervical  vertebrae, 
the  six  first  being  anchylosed,  thirteen  costal  or  dorsal,  and  forty-six  lumbar  and 
caudal,  making  in  all  sixty-six.] 

if  [In  the  Delphinus  Tarsio  there  are  seven  cervical,  the  two  first  being  anchy- 
losed, thirteen  dorsal  or  costal  vertebrae,  corresponding  with  the  pairs  of  ribs,  and 
forty-three  to  the  tail,  making  in  all  sixty-three  vertebrte.] 

§ [We  have  never  found  more  than  thirteen  pairs  of  ribs  in  either  the  Delphinus 
Tursio,  or  Phocsena  communis.  In  the  Grampus  there  are  seven  cervical  vertebrae, 
twelve  costal,  and  forty-four  lumbar  and  caudal;  making  in  all  sixty-three  verte- 
brae. The  Cachalot  has  sixty-one  vertebrae,  and  fourteen  pairs  of  ribs.  The 
nurnber  of  ribs  in  Balsmoptera  rostrata  is  eleven  pairs.] 


344 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


length.  In  the  piked  whale  the  first  rib,  and  in  the  porpoise  the 
three  first,  are  articulated  with  the  sternum.* * * § 

As  a contraction,  corresponding  to  the  neck  in  quadrupeds,  would 
have  been  improper  in  this  order  of  animals,  the  vertebrse  of  the 
neck  are  thin,  to  make  the  distance  between  the  head  and  shoulders 
as  short  as  possible;  and  in  the  small  bottle-nose  whale  are  only  six 
in  number.f 

The  structure  of  the  bones  is  similar  to  that  of  the  bones  of  quad- 
rupeds: they  are  composed  of  an  animal  substance,  and  an  earth 
that  is  not  animal ; these  seem  only  to  be  mechanically  mixed,  or 
rather  the  earth  thrown  into  the  interstices  of  the  animal  part. 
In  the  bones  of  fishes  this  does  not  seem  to  be  the  case,  the  earth 
in  many  fish  being  so  united  with  the  animal  part  as  to  render 
the  whole  transparent,  which  is  not  the  case  when  the  animal 
part  is  removed  by  steeping  the  bone  in  caustic  alkali ; nor  is  the 
animal  part  so  transparent  when  deprived  of  the  earth.  The 
bones  are  less  compact  than  those  of  quadrupeds  that  are  similar 
to  them. 

Their  form  somewhat  resembles  what  takes  place  in  the  quad- 
ruped, at  least  in  those  whose  uses  are  similar,  as  the  vertebrce,. 
ribs,  and  bones  of  the  anterior  extremities  have  their  articulations 
in  part  alike,  although  not  in  all’of  them.  The  articulation  of  the 
lower  jaw,  of  the  carpus,  metacarpus,  and  fingers  are  exceptions. 
The  articulation  of  the  lower  jaw  is  not  by  simple  contact  either 
single  or  double,  joined  by  a capsular  ligament,  as  in  the  quadruped, 
but  by  a very  thick  intermediate  substance  of  the  ligamentous  kind, 
so  interwoven  that  its  parts  move  on  each  other,  in  the  interstices 
of  which  is  an  oil.  This  thick  matted  substance  may  answer  the 
same  purpose  as  the  doublejoint  in  the  quadruped.J 

Tlie  two  fins  are  analogous  to  the  anterior  extremities  of  the 
quadruped,  and  are  also  somewhat  similar  in  construction.  A fin 
is  composed  of  a scapula,  os  hurneri,  ulna,  radius,  carpus,  and  meta- 
carpus, in  which  last  may  be  included  the  fingers,  because  the  number 
of  bones  are  those  wliich  might  be  called  fingers,  although  they  are 
not  separated,  but  included  in  one  general  covering  with  the  meta- 
carpus. They  have  nothing  analogous  to  the  thumb, § and  the 

* [In  our  dissections  we  find  five  pairs  of  ribs  articulated  to  the  sternum  in  the 
porpoise.  In  the  Hyperoodon  there  are  also  five  pairs  of  sternal  ribs.  In  the 
piked  whale  {Bal.  roslrata)  the  floatinor  extremities  of  the  ten  posterior  pairs  of 
ribs  are  attached  to  strong  ligamentous  decussating  bands,  which  form  a middle 
tendinous  raphe,  in  the  place  of  a sternum.] 

f ['I’he  true  number  of  cervical  vertebrae  is  seven  in  all  the  carnivorous  Cetacea, 
as  the  holes  for  the  transmission  of  the  cervical  nerves  distinctly  demonstrate. 
In  the  manatee  there  are  only  six.  The  more  or  less  anchylosed  condition  of 
these  vertebrce  gives  fixity  to  the  head.  The  corresponding  region  of  the  spine  in 
fish  is  rendered  inflexible;  and  in  the  burrowing  armadillos  some  of  the  cervical 
vertebrae  are  anchylosed,  which  structure  in  all  these  cases  is  designed  to  afford 
the  requisite  power  to  the  head  for  overcoming  pressure  ] 

4:  [See  the  Preparation  No.  240,  Physiological  Series,  Hunterian  Museum.] 

§ [i  c.  No.  digit  analogous  in  the  opposable  property  which  essentially  charac- 
terizes a thumb;  b.ut  the  homologous  digit,  the  fifth  on  the  radial  side,  is  presen-t 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC, 


345 


number  of  bones  in  each  is  different:  in  the  fore-finger  there  are 
five  hones,  in  the  middle  and  ring-finger  seven,  and  in  the  little  finger 
four.  The  articulation  of  the  carpus,  metacarpus,  and  fingers  is 
different  from  that  of  the  quadruped,  not  being  by  capsular  liga- 
ment, but  by  intermediate  cartilages  connected  to  each  bone. 
The  cartilages  between  the  different  bones  of  the  fingers  are  of 
considerable  length,  being  nearly  equal  to  one  half  of  that  of  the 
bone:  and  this  construction  of  the  parts  gives  firmness  with  some 
degree  of  pliability  to  the  whole. 

As  this  order  of  animals  cannot  be  said  to  have  a pelvis,  they  of 
course  have  no  os  sacrum,  and  therefore  the  vertehrm  are  continued 
on  to  the  end  of  the  tail,  but  with  no  distinction  between  those  of 
the  loins  and  tail.  But  as  those  vertebrse  alone  would  not  have  had 
sufficient  surface  to  give  rise  to  the  muscles  requisite  to  the  motion 
of  the  tail,  there  are  bones  added  to  the  fore  part  of  some  of  the 
first  vertebrae  of  the  tail,*  similar  to  the  spinal  processes  on  the 
posterior  surface. 

From  all  these  observations  we  may  infer  that  the  structure, 
formation,  arrangement,  and  the  union  of  the  bones  which  compose 
the  forms  of  parts  in  this  order  of  animals  are  much  upon  the  same 
principle  as  in  quadrupeds. 

The  flesh  of  muscles  of  this  order  of  the  animals  is  red,  resem- 
bling that  of  most  quadrupeds,  perhaps  more  like  that  of  the  bull  or 
horse  than  any  other  animal;  som.e  of  it  is  very  firm,  and  about 
the  breast  and  belly  it  is  mixed  with  tendon. 

Although  the  body  and  tail  is  composed  of  a series  of  bones  con- 
nected together  and  moved  as  in  fish,  yet  it  has  its  movement  pro- 
duced by  long  muscles,  with  long  tendons,  which  renders  the  body 
thicker  while  the  tail  at  its  stem  is  smaller  than  that  of  any  other 
swimmer,  whose  principal  motion  is  the  same.  Why  this  mode  of 
applying  the  moving  powers  should  not  have  been  used  in  fish  is 
probably  not  so  easily  answered  ; but  in  fish  the  muscles  of  the  body 
are  of  nearly  the  same  length  as  the  vertebrae. 

The  depressor  muscles  of  the  tail,  which  are  similar  in  situation 
to  the  psoae,  make  two  very  large  ridges  on  the  lower  part  of  the 
cavity  of  the  belly,  rising  much  higher  than  the  spine,  and  the  lower 
part  of  aorta  passes  between  them, 

These  two  large  muscles,  instead  of  being  inserted  into  two  ex- 
in most  cetacea.  It  has  two  phalanges  in  the  Porpoise,  and  four  phalanges  in  the 
Black-fish  {Dtlpldnus  Glabiceps).  It  is  wanting  in  the  Balssiiopiera  Australis.'] 

* [These  bones  protect  the  great  vascular  trunk  below,  as  the  upper  processes 
protect  the  spinal  chord  above,  the  bodies  of  the  vertebrae.  The  former  or  inferior 
arches  are  termed  by  Geoffrey  paraaux,  or  paravertebral  elements;  the  latter  the 
periaux,  or  perivertebral  elements.  I have  proposed  to  denominate  those  which 
protect  the  vascular  trunks  ‘ aimapophyses  those  which  protect  the  nervous 
trunk  ‘ neurapophyses.’  The  aimapophyses  are  articulated  in  the  Cetacea  at  the 
interspaces  of  the  bodies  of  the  vertebras,  and  connected  with  the  intervertebral 
substance.  In  the  dorsal  vertebrae  of  the  tortoise,  and  in  the  sacrum  of  the  ostrich, 
the  neurapophyses,  or  superior  arches,  are  similarly  placed  with  respect  to  the 
vertebral  centres  or  bodies.] 


346 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


tremities  as  in  the  quadruped,  go  to  the  tail,  which  may  be  consi- 
dered in  this  order  of  animals  as  the  two  posterior  extremities 
united  into  one. 

Their  muscles  a very  short  time  after  death  lose  their  fibrous 
structure,  become  as  uniform  in  texture  as  clay  or  dough,  and  even 
softer.  This  change  is  not  from  putrefaction,  as  they  continue  to 
be  free  from  any  ofiensive  smell,  and  is  most  remarkable  in  those 
of  the  psoae  muscles  and  those  of  the  back. 

Of  the  Construction  of  the  Tail. 

The  mode  in  which  the  tail  is  constructed  is  perhaps  as  beautiful, 
as  to  the  mechanism,  as  any  part  of  the  animal.  It  is  wholly  com- 
posed of  three  layers  of  tendinous  fibres,  covered  by  the  common 
cutis  and  cuticle  ; two  of  these  layers  are  external,  the  other  inter- 
nal. The  direction  of  the  fibres  of  the  external  layers  is  the  same 
as  in  the  tail,  forming  a stratum  about  one-third  of  an  inch  thick 
but  varying  in  this  respect  as  the  tail  is  thicker  or  thinner.  The 
middle  layer  is  composed  entirely  of  tendinous  fibres,  passing  di- 
rectly across,  between  the  two  external  ones  above  described,  their 
length  being  in  proportion  to  the  thickness  of  the  tail : a structure 
which  gives  amazing  strength  to  this  part. 

The  substance  of  the  tail  is  so  firm  and  compact  that  the  vessels 
retain  their  dilated  state  even  when  cut  across;  and  this  section 
consists  of  a large  vessel  surrounded  by' as  many  small  ones  as  can 
come  in  contact  with  its  external  surface : which  of  these  are  arteries 
and  which  veins  I do  not  know. 

The  fins  are  merely  covered  with  a strong  condensed  adipose 
membrane. 


Of  the  Fat. 

The  fat  of  this  order  of  animals,  except  the  spermaceti,  is  what 
we  generally  term  oil.  It  does  not  coagulate  in  our  atmosphere, 
and  is  probably  the  most  fluid  of  animal  fats;  but  the  fat  of  every 
difl’erent  order  of  animals  has  not  a peculiar  degree  of  solidity,  some 
having  it  in  the  same  state,  as  the  horse  and  bird.  What  I believe 
approaches  nearest  to  spermaceti  is  the  fat  of  ruminating  animals, 
called  tallow. 

The  fat  is  differently  situated  in  different  orders  of  animals,  pro- 
bably for  particular  purposes ; at  least  in  some  we  can  assign  a 
final  intention.  In  the  animals  which  are  the  subject  of  the  present 
paper  it  is  found  principally  on  the  outside  of  the  muscles,  imm.e- 
diately  under  the  skin,  and  is  in  considerable  quantity.  It  is  rarely 
to  be  met  with  in  the  interstices  of  the  muscles,  or  in  any  of  the 
cavities,  such  as  the  abdomen  or  about  the  heart. 

In  animals  of  the  same  class  living  on  land  the  fat  is  more  dif- 


* [In  the  Bat.  rostrata.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


347 


fused ; it  is  situated,  more  especially  when  old,  in  the  interstices  of 
muscles,  even  between  the  fasciculi  of  muscular  fibres,  and  is 
attached  to  many  of  the  viscera  ; but  many  parts  are  free  from  fat, 
unless  when  diseased,  as  the  penis,  scrotum,  testicle,  eyelid,  liver, 
lungs,  brain,  spleen,  &c. 

In  fish,  its  situation  is  rather  particular,  and  is  most  commonly  in 
two  modes:  in  the  one  diffused  through  the  whole  body  of  the  fish, 
as  in  the  salmon,  herring,  pilchard,  sprat,  &c. ; in  the  other,  it  is 
found  in  the  liver  only,  as  in  all  of  the  ray  kind,  cod,  and  in  all 
those  called  white-fish,  there  being  none  in  any  other  part  of  the 
body.*  The  fat  of  fish  appears  to  be  diffused  through  the  substance 
of  the  parts  which  contain  it,  but  is  probably  in  distinct  cells.  In 
some  of  these  fish,  where  it  is  diffused  over  the  whole  body,  it  is 
more  in  some  parts  than  others,  as  on  the  belly  of  the  salmon, 
where  it  is  in  larger  quantity. 

The  fat  is  differently  inclosed  in  different  orders  of  animals.  In 
the  quadruped,  those  of  the  seal  kind  excepted,  in  the  bird,  amphibia, 
and  in  some  fish,  it  is  contained  in  loose  cellular  membrane,  as  if 
in  bags,  composed  of  sm.aller  ones,  by  which  means  the  larger  admit 
of  motion  on  one  another  and  on  their  connecting  parts ; which 
motion  is  in  a greater  or  less  degree,  as  is  proper  or  useful.  Where 
motion  could  answer  no  purpose,  as  in  the  bones,  it  is  confined  in 
still  smaller  cells.  The  fat  is  in  a less  degree  in  the  soles  of  the 
feet,  palms  of  the  hands,  and  in  the  breasts  of  many  animals.  In 
this  order  of  animals  and  the  seal  kind,  as  far  as  I yet  know,  it  is 
disposed  of  in  two  ways  : the  small  quantity  found  in  the  cavities 
of  the  body  and  interstices  of  parts  is  in  general  disposed  in  the 
same  way  as  in  quadrupeds ; but  the  external,  which  includes  the 
principal  part,  is  inclosed  in  a reticular  membrane,  apparently  com- 
posed of  fibres  passing  in  all  directions,  which  seem  to  confine  its 
extent,  allowing  it  little  or  no  motion  on  itself,  the  whole  when  dis- 
tended forming  almost  a solid  body.  This,  however,  is  not  always 
the  case  in  every  part  of  animals  of  this  order  ; for  under  the  head, 
or  what  may  be  rather  called  neck,  of  the  bottle-nose,  the  fat  is  con- 
fined in  larger  cells,  admitting  of  motion.  This  reticular  membrane 
is  very  fine  in  some,  and  very  strong  and  coarse  in  others,  and  even 
varies  in  different  parts  of  the  same  animal.  It  is  fine  in  the  por- 
poise, spermaceti,  and  large  whalebone  whale;  coarse  in  the 
grampus  and  small  whalebone  whale  :f  in  all  of  them  it  is  finest  on 
the  body,  becoming  coarser  towards  the  tail,  which  is  composed  of 
fibres  without  any  fiit,  which  is  also  the  case  in  the  covering  of  the 
fins.  This  reticular  net-work  in  the  seal  is  very  coarse ; and  in 
those  which  are  not  fat,  when  it  collapses,  it  looks  almost  like  a fine 
net  with  small  meshes.  This  structure  confines  the  animal  to  a 


* The  sturgeon  is,  however,  an  exception,  having  its  fat  in  particular  situations, 
and  in  the  interstices  of  parts,  as  in  other  animals. 

t Where  it  is  fine  it  yields  the  largest  quantity  of  oil,  and  requires  the  least 
boiling. 


348 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


determined  shape,  whereas  in  quadrupeds  fat  when  in  great  quan- 
tity destroys  all  shape. 

The  fat  differs  in  consistence  in  different  animals,  and  in  different 
parts  of  the  same  animal,  in  which  its  situation  is  various.  In 
quadrupeds  some  have  the  external  fat  softer  than  the  internal,  and 
that  inclosed  in  bones  is  softest  nearer  to  their  extremities.  Rumi- 
nating animals  have  that  species  of  fat  called  tallow,  and  in  their 
bones  they  have  either  hard  fat,  or  marrow,  or  fluid  fat,  called 
neat’s-foot  oil.  In  this  order  of  animals  the  internal  fat  is  the  least 
fluid,  and  is  nearly  of  the  consistence  of  hog’s-lard  ; the  external  is 
the  common  train  oil.  But  the  spermaceti  whale  differs  from  every 
other  animal  I have  examined,  having  the  two  kinds  of  fat  just  men- 
tioned, and  another,  which  is  totally  different,  called  spermaceti,  of 
which  I shall  give  a particular  account. 

What  is  called  spermaceti  is  found  everywhere  in  the  body  in 
small  quantity,  mixed  with  the  common  fat  of  the  animal,  bearing 
a very  small  proportion  to  the  other  fat.  In  the  head  it  is  the 
reverse,  for  there  the  quantity  of  spermaceti  is  large  when  com- 
pared to  that  of  the  oil,  although  they  are  mixed,  as  in  the  other 
parts  of  the  body. 

As  the  spermaceti  is  found  in  the  largest  quantity  in  the  head, 
and  in  what  would  appear  on  a slight  view  to  be  the  cavity  of  the 
skull,  from  a peculiarity  in  the  shape  of  that  bone,  it  has  been 
imagined  by  some  to  be  the  brain. 

These  two  kinds  of  fat  in  the  head  are  contained  in  cells,  or  cel- 
lular membrane,  in  the  same  manner  as  the  fat  in  other  animals  ; 
but  besides  the  common  cells  there  are  larger  ones,  or  ligamentous 
partitions,  going  across,  the  better  to  support  the  vast  load  of  oil  of 
which  the  bulk  of  the  head  is  principally  made  up. 

There  are  two  places  in  the  head  where  this  oil  lies;  these  are 
situated  along  its  upper  and  lower  part,  between  them  pass  the  nos- 
trils, and  a vast  number  of  tendons  going  to  the  nose  and  different 
parts  of  the  head. 

The  purest  spermaceti  is  contained  in  the  smallest  and  least  liga- 
mentous cells : it  lies  above  the  nostril,  all  along  the  upper  part  of 
the  head,  immediately  under  the  skin  and  common  adipose  mem- 
brane. These  cells  resemble  those  which  contain  the  common  fat 
in  the  other  parts  of  the  body  nearest  the  skin.  That  which  lies 
above  the  roof  of  the  mouth,  or  between  it  and  the  nostril,  is  more 
intermixed  with  a ligamentous  cellular  membrane,  and  lies  in  cham- 
bers whose  partitions  are  perpendicular.  These  chambers  are 
smaller  the  nearer  to  the  nose,  becoming  larger  and  larger  towards 
the  back  part  of  the  head,  where  the  spermaceti  is  more  pure. 

This  spermaceti,  when  extracted  cold,  has  a good  deal  the  appear- 
ance of  the  internal  structure  of  a water-melon,  and  is  found  in 
rather  solid  lumps. 

About  the  nose,  or  anterior  part  of  the  nostril,  I discovered  a 
great  manj^  vessels,  having  the  appearance  of  a plexus  of  veins, 
some  as  large  as  a finger.  On  examining  them,  I found  they  were 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


349 


loaded  with  the  spermaceti  and  oil,  and  that  some  had  correspond- 
ing arteries.  They  were  most  probably  lymphatics;*  therefore  I 
should  suppose  that  their  contents  had  been  absorbed  from  the  cells 
of  the  head.  We  may  the  more  readily  suppose  this  from  finding 
many  of  the  cells  or  chambers  almost  empty;  and  as  we  may  rea- 
sonably believe  that  this  animal  had  been  some  time  out  of  the  seas 
in  which  it  could  procure  proper  food,  it  had  perhaps  lived  on  the 
superabundance  of  oil. 

The  solid  masses  are  what  are  brought  home  in  casks  for  sperma- 
ceti. 

I found,  by  boiling  this  substance,  that  I could  easily  extract  the 
spermaceti  and  oil  which  floated  on  the  top  from  the  cellular  mem- 
brane. When  I skimmed  off  the  oily  part,  and  let  it  stand  to  cool, 
I found  that  the  spermaceti  crystallized,  and  the  whole  became 
solid  ; and  by  laying  this  cake  upon  any  spongy  substance,  as  chalk, 
or  on  a hollow  body,  the  oil  drained  all  off,  leaving  the  spermaceti 
pure  and  white.  These  crystals  were  only  attached  to  each  other 
by  edges,  forming  a spongy  mass  ; and  by  melting  this  pure  sperma- 
ceti, and  allowing  it  to  crystallize,  it  was  reduced  in  appearance 
to  half  its  bulk,  the  crystals  being  smaller  and  more  blended,  conse- 
quently less  distinct. 

The  spermaceti  mixes  readily  with  other  oils,  while  it  is  in  a fluid 
state,  but  separates  or  crystallizes  whenever  it  is  cooled  to  a cer- 
tain degree,  like  two  different  salts  being  dissolved  in  water,  one  of 
which  will  crystallize  with  a less  degree  of  evaporation  than  the 
other  ; or,  if  the  water  is  warm  and  fully  saturated,  one  of  the  salts 
will  crystallize  sooner  than  the  other  while  the  solution  is  cooling. 
I wanted  to  see  whether  spermaceti  mixed  equally  well  with  the 
expressed  oils  of  vegetables  w'hen  warm,  and  likewise  separated  and 
crystallized  when  cold  ; and  on  trial  there  seemed  to  be  no  difference. 
When  very  much  diluted  with  the  oil,  it  is  dissolved  or  melted  by 
a much  smaller  degree  of  heat  than  when  alone  ; and  this  is  the 
reason,  perhaps,  that  it  is  in  a fluid  state  in  the  living  body. 

If  the  quantity  of  spermaceti  is  small  in  proportion  to  the  other 
oil,  it  is  perhaps  nearly  in  that  proportion  longer  in  crystallizing  ; 
and  when  it  does  crystallize,  the  crystals  are  much  smaller  than 
those  that  are  formed  where  the  proportion  of  spermaceti  is  greater. 
From  the  slowness  with  which  the  spermaceti  crystallizes  when 
much  diluted  with  its  oil,  from  a considerable  quantity  being  to  be 
obtained  in  that  way,  and  from  its  continuing  for  years  to  crystal- 
lize, one  would  be  induced  to  think  that  perhaps  the  oil  itself  is  con- 
verted into  spermaceti. 

It  is  most  likely  that  if  we  could  discover  the  exact  form  of  the 
different  crystals  of  oils,  w e should  thence  be  able  to  ascertain  both  the 
different  sorts  of  vegetable  oils,  expressed  and  essential,  and  the  dif- 
ferent sorts  of  animal  oils,  much  better  than  by  any  other  means  ; in 
the  same  manner  as  we  know  salts  by  the  forms  into'  which  they  shoot 

* [See  the  Preparation  No.  862,  Physiological  Series,  Hunterian  Museum.] 

31 


350 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  spermaceti  does  not  become  rancid  or  putrid  nearly  so  soon 
as  the  other  animal  oils,  which  is  most  probably  owing  to  the 
spermaceti  being  for  the  most  part  in  a solid  state ; and  I should 
suppose  that  few  oils  would  become  so  soon  rancid  as  they  do  if 
they  were  always  preserved  in  that  degree  of  cold  which  rendered 
them  solid  ; neither  does  this  oil  become  so  soon  putrid  as  the  flesh 
of  the  animal,  and  therefore,  altliough  the  oil  in  the  cells  appeared 
to  be  putrid  before  boiling,  it  was  sweet  when  deprived  of  the  cel- 
lular substance.  The  spermaceti  is  rather  heavier  than  the  other  oil. 

In  this  animal  then  we  find  two  sorts  of  oil,  besides  the  deeper- 
seated  fat,  common  to  all  of  this  class,  one  of  which  crystallizes 
with  a much  less  degree  of  cold  than  the  other,  and  of  course  re- 
quires a greater  degree  of  heat  to  melt  it,  and  forms,  perhaps,  the 
largest  crystals  of  any  expressed  oil  we  know:  yet  the  fluid  oil  of 
this  animal  will  crystallize  in  an  extreme  hard  frost  much  sooner 
than  most  essential  oils,  though  not  so  soon  as  the  expressed  oils  of 
vegetables.  Camphire,  however,  is  an  exception,  since  it  crystal- 
lizes in  our  warmest  weather,  and-  when  melted  with  expressed  oil 
of  vegetables,  if  the  oil  is  too  much  saturated  for  that  particular  de- 
gree of  cold,  crystallizes  exactly  like  spermaceti. 

In  the  ox  the  tallow,  and  what  is  called  neat’s-foot  oil,  crystallize 
in  different  degrees  of  cold.  The  tallow  congeals  with  rather  less 
cold  than  the  spermaceti,  but  the  other  oil  is  similar  to  what  is 
called  the  train  oil  in  the  whale. 

I have  endeavoured  to  discover  the  form  of  the  crystals  of  dif- 
ferent sorts  of  oil,  hut  could  never  determine  exactly  what  that 
was,  because  I could  never  find  any  of  the  crystals  single,  and  by 
being  always  united  the  natural  form  was  not  distinct. 

It  is  the  adipose  covering  from  all  of  the  whale  kind  that  is 
brought  home  in  square  pieces,  called  flitches,  and  which,  by  being 
boiled,  yields  the  oil  on  expression,  leaving  the  cellular  membrane. 
When  these  flitches  have  become  in  some  degree  putrid,  there  issue 
two  sorts  of  oil  ; the  first  is  pure,  the  last  seems  incorporated  with 
part  of  the  animal  substance,  which  has  become  easy  of  solution 
from  its  putridity,  forming  a kind  of  butter.  It  is  unctuous  to  the 
touch,  ropy,  coagulates,  or  becomes  harder  by  cold,  swims  upom 
water,  not  being  soluble  in  it;  and  the  pure  oil,  separating  in  the 
same  manner  from  this,  swims  above  all. 

What  remains  after  all  the  oil  is  extricated  retains  a good  deal 
of  its  form,  is  almost  wholly  convertible  into  glue,  and  is  sold  for 
that  purpose. 

The  cellular,  or  rather  what  should  be  called  the  uniting  mem- 
brane, in  this  order  of  animals  is  similar  to  that  in  the  quadruped; 
we  find  it  uniting  muscle  to  muscle,  and  muscle  to  bone,  for  their 
easy  motion  on  one  another. 

The  cellular  membrane,  which  is  the  receptacle  for  the  oil  near 
the  surface  of  the  body,  is  in  general  very  different  from  that  in  the' 
quadruped,  as  has  been  already  observed. 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


351 


Of  the  Skin. 

The  coverine:  of  this  order  of  animals  consists  of  a cuticle  and 
cutis. 

The  cuticle  is  somewhat  similar  to  that  on  the  sole  of  the  foot  in 
the  human  species,  and  appears  to  be  made  up  of  a number  of  layers, 
which  separate  by  slight  putrefaction  ; but  this  I suspect  arises  in 
some  degree  from  there  being  a succession  of  cuticles  formed.  It 
has  no  degree  of  elasticity  or  toughness,  but  tears  easily ; nor  do 
its  fibres  appear  to  have  any  particular  direction.  The  internal 
stratum  is  tough  and  thick,  and  in  the  spermaceti  whale  its  internal 
surface,  when  separated  from  the  cutis,  is  just  like  coarse  velvet, 
each  pile  standing  firm  in  its  place  ; but  this  is  not  so  distinguisha- 
ble in  some  of  the  others,  although  it  appears  rough  from  the  in- 
numerable perforations. 

It  is  the  cuticle  that  gives  the  colour  to  the  animal ; and  in  parts 
that  are  dark  I think  I have  seen  a dirty-coloured  substance  washed 
away  in  the  separation  of  the  cuticle  from  the  cutis,  which  must  be 
a kind  of  rete  mucosum. 

The  cutis  in  this  tribe  is  extremely  villous  on  its  external  surface, 
answering  to  the  rough  surface  of  the  cuticle,  and  forming  in  some 
parts  small  ridges,  similar  to  those  on  the  human  fingers  and  toes. 
These  villi  are  soft  and  pliable;  they  float  in  water,  and  each  is 
longer  or  shorter,  according  to  the  size  of  the  animal.  In  the  sper- 
maceti whale  they  were  about  a quarter  of  an  inch  long;  in  the 
grampus,  bottle-nose,  and  piked  whales,  much  shorter;  in  all,  they 
are  extremely  vascular. 

The  cutis  seems  to  be  the  termination  of  the  cellular  membrane 
of  the  body  more  closely  united,  having  smaller  interstices  and  be- 
coming more  compact.*  This  alteration  in  the  texture  is  so  sudden 
as  to  make  an  evident  distinction  between  what  is  solely  connecting 
membrane,  and  skin,  and  is  most  evident  in  lean  animals;  for  in 
the  change  from  fat  to  lean  the  skin  does  not  undergo  an  alteration 
equal  to  what  takes  place  in  the  adipose  membrane,  although  it  may 
be  observed  that  the  skin  itself  is  diminished  in  thickness.  In  fat 
animals  the  distinction  between  skin  and  cellular  membrane  is 
much  less,  the  gradation  from  the  one  to  the  other  seeming  to  be 
slower ; for  the  cells  of  both  membrane  and  skin  being  loaded  with 
fat,  the  whole  has  more  the  appearance  of  one  uniform  substance. 
The  uniformity  of  the  adipose  membrane  and  skin  is  most  observ- 
able in  the  whale,  seal,  hog,  and  the  human  species,  and  is  not  only 
visible  in  the  raw,  but  in  the  dressed  hides;  for  in  dressed  skins  the 
external  is  much  more  compact  in  texture  than  the  inner  surface, 
and  is  in  common  very  tough. 

* [That  is  to  say,  the  denser  external  layer  or  dermis,  and  the  more  open  cel- 
lular and  fibrous  structure  below,  which  in  the  Cetacea  is  loaded  with  oil,  are 
essentially  modifications  of  one  and  the  same  structure.  It  is  this  combination 
of  the  dermal  with  the  adipose  tissues  in  the  blubber  of  the  whale  which  serves 
to  retain  the  internal  heat,  and  at  the  same  time  resists  the  external  pressure, 
which  must  be  occasionally  enormous.] 


352 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


In  some  animals  the  cutis  is  extremely  thick,  and  in  some  parts 
much  more  so  than  in  others ; where  very  thick  it  appears  to  be 
intended  as  a defence  against  the  violence  of  their  own  species  or 
other  animals.  In  most  quadrupeds  it  is  muscular,  contracting  by 
cold,  and  relaxing  by  heat.  Many  other  stimulating  substances 
make  it  contract,  but  cold  is  probably  that  stimulus  by  which  it  was 
intended  to  be  generally  aflected. 

The  skin  is  extremely  elastic  in  the  greatest  number  of  quadru- 
peds, and  in  its  contracted  state  may  be  said  to  be  rather  too  small 
for  the  body  ; by  this  elasticity  it  adapts  itself  to  the  changes  which 
are  constantly  taking  place  in  the  parts,  and  it  is  from  the  want  of 
it  that  it  becomes  too  large  in  some  old  animals.  In  all  animals  it 
is  more  elastic  in  some  parts  than  others,  especially  in  those  where 
there  is  the  greatest  motion.  How  far  these  variations  take  place 
in  the  whale  I do  not  exactly  know  ; but  a loose  elastic  skin  in  this 
tribe  would  appear  to  be  improper  as  an  universal  covering,  con- 
sidering the  progressive  motion  of  the  animal,  and  the  medium  in 
■which  it  moves;  therefore  it  appears  to  be  kept  always  on  the 
stretch,  by  the  adipose  membrane  being  loaded  with  fat,  which  does 
not  allow  the  skin  to  recede  when  cut.  It  is,  however,  more  elastic 
at  the  setting  on  of  the  eyelids,  round  the  opening  of  the  prepuce, 
the  nipples,  the  setting  on  of  the  fins,  and  under  the  jaw,  to  allow 
of  motion  in  those  parts  ; and  here  there  is  more  reticular,  and  less 
adipose  membrane.  But  in  the  piked  whale  there  is  probably  one 
of  the  most  striking  instances  of  an  elastic  cuticular  contraction  ; 
for  though  the  whole  skin  of  the  fore  part  of  the  neck  and  breast  of 
the  animal,  as  far  down  as  the  middle  of  the  belly,  be  extremely 
elastic  ; yet  to  render  it  still  more  so' it  is  ribbed  longitudinally,  like 
a ribbed  stocking,  which  gives  an  increased  lateral  elasticity. 
These  ribs  are,  when  contracted,  about  five-eighths  of  an  inch  broad, 
covered  with  the  common  skin  of  the  animal;  but  in  the  hollow 
part  of  the  rib  it  is  of  a softer  texture,  with  a thinner  cuticle.  This 
part  is  possessed  of  the  greatest  elasticity;  why  it  should  be  so 
elastic  is  difficult  to  say,  as  it  covers  the  thorax,  which  can  never 
be  increased  in  size;  yet  there  must  be  some  peculiar  circumstance 
in  the  oeconomy  of  the  species  requiring  this  structure,  which  we 
as  yet  know  nothin^  of.* ** 

The  skin  is  intended  for  various  purposes.  It  is  the  universal 
covering  given  for  the  defence  of  all  kinds  of  animals  ; and  that  it 
might  answer  this  purpose  well,  it  is  the  seat  of  one  of  the  senses.-]- 

* [A  strong-  and  extensive  cutaneous  muscle  is  intimately  connected  -with 
the  skin,  but  is  separated  by  a loose  cellular  texture  from  the  deep-seated  mus- 
cles.] 

f [The  skin  of  the  Cetacea  has  been  made  the  subject  of  a special  and  minute 
study  by  MM.  Breschet  and  Roussel  de  'Yauzeme,  who  distinguish  in  it,  as  in 
that  of  other  Mammalia,  six  chief  constituents,  which  either  penetrate  or  are 
superimposed  upon  one  another,  as  follows  : 

1.  The  derm  or  corium  (/e  derme),  a dense  fibrous  cellular  texture,  which  con- 
tains and  protects  all  the  other  parts  of  the  skin.  In  the  whale  it  is  constantly 
white  and  opake,  and  its  peripheral  surface  presents  a series  of  papilla,  the 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


353 


Of  the  Mode  of  catching  their  Food. 

The  mouths  of  animals  are  the  first  parts  to  be  considered 
respecting  nourishment  or  food,  and  are  so  much  connected  with 
everything  relative  to  it  as  not  only  to  give  good  hints  whether  the 
food  is  vegetable  or  animal,  but  also  respecting  the  particular  kind 
of  either,  especially  of  animal  food.  The  mouth  not  only  receives 
the  food,  but  is  the  immediate  instrument  for  catching  it.  As  it  is 
a compound  instrument  in  many  animals,  having  parts  of  various 
constructions  belonging  to  it,  I shall  at  present  consider  it  in  this 
tribe  no  further  than  as  connected  with  their  mode  of  catching  food, 
and  adapting  and  disposing  it  for  being  swallowed.  It  is  probable 
that  these  animals  do  not  require  either  a division  of  the  food,  or  a 
mastication  of  it  in  the  mouth,  but  swallow  whatever  they  catch 
whole  ; for  we  do  not  find  any  of  them  furnished  with  parts  capable 
of  producing  either  effect.  The  mouth  in  most  of  this  tribe  is  well 
adapted  for  catching  the  food ; the  jaws  spread  as  they  go  back, 
making  the  mouth  proportionally  wider  than  in  many  other 
animals. 

There  is  a very  great  variety  in  the  formation  of  the  mouths 

intervals  of  which  are  occupied  by  the  epidermis,  which  forms  for  each  a 
sheath. 

2.  The  papillary  bodies  {les  corps papillaires')  consist  of  papillae  covered  by  the 
derm.  They  have  a nacreous  lustre,  and  are  several  lines  in  length  in  the 
whale,  but  are  much  shorter  in  the  common  dolphin  and  porpesse.  These  pa- 
pillae are  composed  of  fibres  penetrated  by  vessels;  they  originate  from  the 
subcutaneous  nervous  plexus,  and  return  back  again  to  the  same;  the  derm 
serves  merely  as  a sheath  to  the  papilla;,  the  extremities  of  which  exercise  the 
sense  of  toucli. 

3.  The  sudorific  apparatus  {Tappareil  sudorifiqiie)  consists  of  soft,  elastic, 
spiral  canals,  which  extend  through  the  entire  thickness  of  the  derm,  and  open 
in  the  intervals  of  the  papillae  by  an  orifice  generally  closed  by  a small  epidermic 
valve. 

4.  The  inhalent  apparatus  (Tappareil  d' inhalation')  is  formed  by  extremely  deli- 
cate canals,  which  are  smooth,  straight,  silvery,  branched,  and  very  ea.sily  rup- 
tured : they  originate  in  a plexus  extended  in  the  dermis  beneath  tlie  sudorific 
canals,  anastomose  together,  and  are  provided  with  partitions.  The  lymphatic 
vessels  have  no  connection  with  these  canals,  which  communicate  directly  with 
the  arteries  and  veins.  They  are  absorbing  canals. 

5.  The  mucous  apparatus  (Tappareil  bknnogene).  This  is  composed  of 
secerning  glands  and  excretory  ducts,  which  open  between  the  papillre  like  the 
orifices  of  the  preceding  canals.  It  is  wholly  contained  in  the  derm,  and  produces 
a mucous  material,  which  by  desiccation  (or  condensation)  becomes  the  cuticle. 
In  the  whales  this  cuticle  actpiires  an  extreme  thickness:  it  is  much  thinner  in 
the  dolphins. a 

6.  The  colorific  apparatus  (Tappareil  chromatogene)  is  likewise  composed  of 
secerning  glands  and  excretory  ducts ; it  is  situated  in  the  first  superior  (pe- 
ripheral) layers  of  the  corium  on  the  right  and  left  sides  of  the  outlet  of  the 
excretory  ducts  of  the  preceding  apparatus,  and  it  pours  out  the  coloured  pro- 
duct at  the  same  point  where  the  mucous  matter  is  excreted,  where  it 
stains  it.] 


“ [In  the  Cachalot  the  external  layer  of  cuticle  is  extremely  fine,  resembling 
gold-beaters’  skin.] 

31* 


854 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


of  this  tribe  of  animals,  whicli  we  have  many  opportunities  of 
knowing,  from  the  head  being  often  brought  home  when  the 
other  parts  of  the  animal  are  rejected  ; a circumstance  which  fre- 
quently leaves  us  ignorant  of  the  particular  species  to  which  it 
belonged. 

Some  catch  their  food  by  means  of  teeth,  which  are  in  both  jaws, 
as  the  porpoise  and  grampus ; in  others,  they  are  only  in  one  jaw, 
as  in  the  spermaceti  whale;* * * §  and  in  the  large  bottle-nose  whale, 
described  by  Dale,  there  are  only  two  small  teeth  in  the  anterior 
part  of  the  lower  jaw.  In  the  narwhale  only  two  tusksf  in  the  fore 
part  of  the  upper  jaw  :J  while  in  some  others  there  are  none  at  all. 
In  those  whicli  have  teeth  in  both  jaws,  the  number  in  each  varies 
considerably;  the  small  bottle-nose  had  forty-six  in  the  upper,  and 
fifty  in  the  lower ; and  in  the  jaws  of  others  there  are  only  five  or 
six  in  each. 

The  teeth  are  not  divisible  into  different  classes,  as  in  quadrupeds  ; 
but  are  all  pointed  teeth,  and  are  commonly  a good  deal  similar. 
Each  tooth  is  a double  cone,  one  point  being  fastened  in  the  gum, 
the  other  projecting  : they  are,  however,  not  all  exactly  of  this 
shape.  In  some  species  of  porpoise  the  fang  is  flattened,  and  thin  at 
its  extremity;  in  the  spermaceti  w'hale  the  body  of  the  tooth  is  a 
little  curved  towards  the  back  part  of  the  mouth;  this  is  also  the 
case  in  some  others.  The  teeth  are  composed  of  animal  substance 
and  earth,  similar  to  the  bony  part  of  the  teeth  in  quadrupeds. 
The  upper  teeth  are  commonly  worn  down  upon  the  inside,  the 
lower  on  the  outside ; this  arises  from  the  upper  jaw  being  in 
general  the  largest. 

The  situation  of  the  teeth,  when  first  formed,  and  their  progress 
afterwards,  as  far  as  I have  been  able  to  observe,  is  very  different 
in  common  from  those  of  the  quadruped.  In  the  quadruped  the 
teeth  are  formed  in  the  jaw,  almost  surrounded  by  the  alveoli,  or 
sockets,  and  rise  in  the  jaw  as  they  increase  in  length  ; the  cover- 
ing of  the  alveoli  being  absorbed,  the  alveoli  afterwards  rise  w'ith 
the  teeth  ; covering  the  whole  fang  ; but  in  this  tribe  the  teeth 
appear  to  form  in,  the  gum,§  upon  the  edge  of  the  jaw,  and  they 

* [The  large  exserted  teeth  are  confined  to  the  lower  jaw  in  this  species,  but 
there  are  a few  smaller  teeth  in  the  upper  jaw  of  the  cachalot.  They  are  de- 
scribed by  Mr.  F.  D.  Bennett  (Zoological  Proceedings,  December,  183G,)  as 
sometimes  occupying  the  bottom  of  the  cavities  which  receive  the  teeth  of  the 
lower  jaw,  but  generally  corresponding  to  the  intervals  between  them.  They 
measure  in  length  about  three  inches,  and  are  slightly  curved  backwards,  are 
developed  in  the  gum,  and  have  only  a very  slight  attachment  to  the  jaw-bone; 
in  two  instances,  Mr.  Bennett  found  eight  on  each  side  of  the  upper  jaw.] 

f [I  call  these  tusks  to  distinguish  them  from  common  teeth.  A tusk  is  that 
kind  of  tooth  which  has  no  bounds  set  to  its  growth,  excepting  by  abrasion,  as 
the  tusk  of  the  elephant,  boar,  sea-horse,  manatee,  &c. 

X [The  concealed  rud'imental  tusk  in  the  male  narwhale  (figured  by  Sir 
E verard  Home  in  the  Philoso])hical  Transactions  for  181  3,  p.  126),  was  first  dis- 
covered by  'I'ichonius,  and  described  by  him  in  a dissertation  entitled  Monoceros 
i’wc/s  Af«;c?A/onoc£ros,  Copenhagen,  1706.] 

§ [In  the  young  porpesse  the  capsules  and  pulps  of  the  teeth  are  always  origi- 
nally imbedded  in  the  substance  of  the  gum,  where  the  first  development  of  the 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


355 


either  sink  in  the  jaw  as  they  lengthen,  or  the  alveoli  rise  to  inclose 
them  ; this  last  is  most  probable,  since  the  depth  of  the  jaw  is  also 
increased,  so  that  the  teeth  appear  to  sink  deeper  and  deeper  in  the 
jaw.  This  formation  is  readily  discovered  in  jaws  not  full  grown  ; 
for  the  teeth  increase  in  number  as  the  jaw  lengthens,  as  in  other 
animals.  The  posterior  part  of  the  jaw  becoming  longer,  the 
number  of  teeth  in  that  part  increases,  the  sockets  becoming  shal- 
lower and  shallower,  and  at  last  being  only  a slight  depression. 

It  would  appear  that  they  do  not  shed  their  teeth,  nor  have  they 
new  ones  formed  similar  to  the  old,  as  is  the  case  with  most  other 
quadrupeds,  and  also  with  the  alligator.  I have  never  been  able  to 
detect  young  teeth  under  the  roots  of  the  old  ones  ; and  indeed  the 
situation  in  which  the)’  are  first  formed  makes  it  in  some  degree 
impossible,  if  the  young  teeth  follow  the  same  rule  in  growing  with 
the  original  ones,  as  they  probably  do  in  most  animals. 

If  it  is  true  that  the  whale  tribe  do  not  shed  their  teeth,  in  what 
way  are  they  supplied  with  new  ones  corresponding  in  size  with 
the  increased  size  of  the  jaw  ? It  would  appear  that  the  jaw,  as  it 
increases  posteriorly,  decays  at  the  symphysis,  and  while  the 
growth  is  going  on,  there  is  a constant  succession  of  new  teeth,  by 
which  means  the  new-formed  teeth  are  proportioned  to  the  jaw. 
The  same  mode  of  grow'th  is  evident  in  the  elephant,  and  in  some 
degree  in  many’  fish;  but  in  these  last  the  absorption  of  the  jaw  is 
from  the  w'hole  of  the  outside  along  where  the  teeth  are  placed. 
The  depth  of  the  alveoli  seems  to  prove  this,  being  shallow  at  the 
back  part  of  the  jaw,  and  becoming  deeper  towards  the  middle,  w'here 
they  are  the  deepest,  tlie  teeth  there  having  come  to  the  full  size. 
From  this  forwards  they  are  again  becoming  shallower,  the  teeth 
being  smaller,  the  sockets  wasting,  and  at  the  symphysis  there  are 
hardly’  any  sockets  at  all.  Tliis  will  make  the  exact  number  of 
teeth  in  any  species  uncertain. 

Some  genera  of  this  tribe  have  another  mode  of  catching  their 
food,  and  retaining  it  till  swallowed,  which  is  by  means  of  the  sub- 
stance called  whalebone.  Of  this  there  are  tw’O  kinds  known;  one 

tootli  commences,  by  the  formation  of  llie  crown.  In  this  structure  we  see  the 
anakiofy  to  tlie  growtli  of  whalebone,  in  which  the  base  of  the  baleen-plates  adhere 
throughout  life  to  the  gum  only.  A superficial  or  less  scrupulous  observer  might 
have  been  led  to  describe  the  development  of  the  teeth  of  the  Cetacea  according 
to  the  ordinary  analogies ; but  what  are  we  to  think  of  that  writer  who  takes  the 
opportunity  to  correct  (!)  Hunter’s  original  and  just  description  of  this  point,  by 
informing  his  readers  that  the  germs  of  the  teeth  are  developed  in  an  alveolar 
cavity  in  other  mammalia  I and,  who,  in  reference  to  the  hypotheses  suggested 
by  Hunter  to  account  for  the  lodgment  of  the  teeth  of  the  Cetacea  in  sockets, 
cjuotes  only  the  first,  for  the  purpose  of  contradicting  it,  asserting  that  the  ‘ cavity 
for  the  reception  of  the  young  teeth  cannot  be  formed  by  the  sinking  of  the  teeth 
in  it,’  but  avoids  all  mention  of  the  second  hypothesis,  which  Hunter  states  to  be 
the  most  probable  of  the  two,  and  which  is  the  true  onel  (See  Knox,  in  the 
Edinburgh  Philosophical  Transactions,  vol.  xi.,p.41l.)  Rapp,  however,  seems 
to  adopt  the  first  view;  he  says,  the  fangs  of  the  teeth  grow  by  degrees  into  the 
groove  of  the  jaw:  ‘•Nach  und  nach  wachst  dann  die  Wurzel  in  Rinne  des 
Kiefers  hinein.”  Cetaceen,  p.  127.] 


356 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


very  large,  probably  from  the  largest  whale  yet  discovered  ; the 
other  from  a smaller  species.* 

This  whalebone,  which  is  placed  on  the  inside  of  the  mouth,  and 
attached  to  the  upper  jaw,  is  one  of  the  most  singular  circum- 
stances belonging  to  this  species,  as  they  have  most  other  parts  in 
common  with  quadrupeds.  It  is  a substance,  I believe,  peculiar  to 
the  whale,  and  of  the  same  nature  as  horn,  which  I shall  use  as  a 
term  to  express  what  constitutes  hair,  nails,  claws,  feathers,  &c. ; 
it  is  wholly  con>posed  of  animal  substance,  and  extremely  elastic.f 

Whalebone  consists  of  thin  plates  of  some  breadth,  and  in  some 
of  very  considerable  length,  their  breadth  and  length  in  some  degree 
corresponding  to  one  another;  and  when  longest  they  are  com- 
monly the  broadest,  but  not  always  so.  These  plates  are  very  dif- 
ferent in  size  in  different  parts  of  the  same  mouth,  more  especially 
in  the  large  whalebone  whale,  whose  upper  jaw  does  not  pass 
parallel  upon  the  under,  but  makes  an  arch,  the  semidiameter  of 
which  is  about  one-fourth  of  the  length  of  the  jaw.  The  head  in 
my  possession  is  nineteen  feet  long,  the  semidiameter  not  quite  five 
feet : if  this  proportion  is  preserved,  those  whales  which  have 
whalebone  fil'teen  feet  long  must  be  of  an  immense  size. 

These  plates  are  placed  in  several  rows,  encompassing  the  outer 
skirts  of  the  upper  jaw,  similar  to  teeth  in  other  animals.  They 
stand  parallel  to  each  other,  having  one  edge  towards  the  circum- 
ference of  the  mouth,  the  other  towards  the  centre  or  cavity. 
They  are  placed  near  together  in  the  piked  whale,  not  being  a 
quarter  of  an  inch  asunder  where  at  the  greatest  distance,  yet 
differing  in  this  respect  in  different  parts  of  the  same  mouth  ; but  in 
the  great  whale  the  distances  are  more  considerable. 

The  outer  row  is  composed  of  the  longest  plates ; and  these  are 
in  proportion  to  the  difl’erent  distances  between  the  two  jaws,  some 
being  fourteen  or  fifteen  feet  long,  and  twelve  or  fifteen  inches  broad ; 
but  towards  the  anterior  and  posterior  part  of  the  mouth,  they  are 
very  short  ; they  rise  for  half  a foot  or  more,  nearly  of  equal 
breadths,  and  afterwards  shelve  off  from  their  inner  side  until  they 
come  near  to  a point  at  the  outer:  the  exterior  of  the  inner  rows 
are  the  longest,  corresponding  to  the  termination  of  the  declivity  of 
the  outer,  and  become  shorter  and  shorter  till  they  hardly  rise 
above  the  gum. 

The  inner  rows  are  closer  than  the  outer,  and  rise  almost  per- 
pendicularly from  the  gum,  being  longitudinally  straight,  and  have 
less  of  the  declivity  than  the  outer.  The  plates  of  the  outer  row 
laterally  are  not  quite  flat,  but  make  a serpentine  line;  more  espe- 
cially in  the  piked  whale  the  outer  edge  is  thicker  than  the  inner. 
All  round  the  line  made  by  their  outer  edges,  runs  a small  white 
bead,  which  is  formed  along  with  the  whalebone,  and  w'ears  down 
with  it.  The  smaller  plates  are  nearly  of  an  equal  thickness  upon 

* [The  largest  species  of  wliale  yet  discovered  is  distinguished  by  the  small- 
sized  baleen-plates,  and  is  the  Balsenoptera  Boops,  as  was  before  observed.] 

f From  this  it  must  appear  that  the  term  bone  is  an  improper  one. 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC, 


357 


both  edges.  In  all  of  them,  the  termination  is  in  a kind  of  hair,  as 
if  the  plate  was  split  into  innumerable  small  parts,  the  exterior 
being  the  longest  and  strongest. 

The  two  sides  of  the  mouth  composed  of  these  rows  meet  nearly 
in  a point  at  the  tip  of  the  jaw,  and  spread  or  recede  latterally  from 
each  other  as  they  pass  back  ; and  at  their  posterior  ends,  in  the 
piked  whale,  they  make  a sweep  inwards,  and  come  very  near  each 
other,  just  before  the  opening  of  the  oesophagus.  In  the  piked 
whale,  there  were  above  three  hundred  in  the  outer  rows  on  each 
side  of  the  mouth.  Each  layer  terminates  in  an  oblique  surface, 
which  obliquity  inclines  to  the  roof  of  the  mouth,  answering 
to  the  gradual  diminution  of  their  length ; so  that  the  whole 
surface  composed  of  these  terminations,  forms  one  plane  rising 
gradually  from  the  roof  of  the  mouth;  from  this  obliquity  of  the 
edge  of  the  outer  row,  we  may  in  some  measure  judge  of  the 
extent  of  the  whole  base,  but  not  exactly,  as  it  makes  a hollow 
curve,  which  increases  the  base. 

The  whole  surface  resembles  the  skin  of  an  animal  covered  with 
strong  hair,  under  wdiich  surface  the  tongue  must  immediately  lie 
when  the  mouth  is  shut:  it  is  of  a light  brown  colour  in  the  piked 
whale,  and  is  darker  in  the  large  whale. 

In  the  piked  whale,  when  the  mouth  is  shut,  the  projecting 
whalebone  remains  entirely  on  the  inside  of  the  lower  jaw,  the 
two  jaw^s  meeting  everywhere  along  their  surface  ; But  how  this 
is  effected  in  the  large  whale  I do  not  certainly  know,  the  horizontal 
plane  made  by  the  lower  jaw  being  straight,  as  in  the  piked  whale; 
but  the  upper  jaw,  being  an  arch,  cannot  be  hid  by  the  lower.  I 
suppose  therefore  that  a bi'oad  upper  lip,  meeting  as  low  as 
the  lower  jaw,  covers  the  whole  of  the  outer  edges  of  the  exterior 
row's. 

The  whalebone  is  continually  w'earing  down,  and  renewing  in  the 
same  proportion,  except  when  the  animal  is  growing  it  is  renewed 
faster  and  in  proportion  to  the  growth. 

The  formation  of  the  whalebone  is  extremely  curious,  being  in  one 
respect  similar  to  that  of  the  hair,  horns,  spurs,  &c.  ; but  it  has 
besides  another  mode  of  growth  and  decay  equally  singular. 

These  plates  form  upon  a thin  vascular  substance,  not  imme- 
diately adhering  to  the  jaw-bone,  but  having  a more  dense  substance 
between,  which  is  also  vascular.  This  substance,  w'hich  may  be 
called  the  nidus  of  the  whalebone,  sends  out  (the  above)  thin 
broad  processes,  answering  to  each  plate,  on  w’hich  the  plate 
is  formed,  as  the  cock’s  spur,  or  the  bull’s  horn  on  the  bony  core, 
or  a tooth  on  its  pulp  ; so  that  each  plate  is  necessarily  hollow  at 
its  growing  end,  the  first  part  of  the  grow'th  taking  place  on  the 
inside  of  this  hollow. 

Besides  this  mode  of  growth,  w'hich  is  common  to  all  such  sub- 
stances, it  receives  additional  layers  on  the  outside,  which  are 
formed  upon  the  above-mentioned  vascular  substance  extended 
along  the  surface  of  the  jaw.  This  part  also  forms  upon  it  a semi- 


358 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


horny  substance  between  each  plate,  which  is  very  white,  rises 
with  tlie  whalebone,  and  becomes  even  with  the  outer  edge  of  the 
jaw,  and  the  termination  of  its  outer  part  forms  the  bead  above- 
mentioned.  This  intermediate  substance  fills  up  the  spaces  between 
the  plates  as  high  as  the  jaw,  acts  as  abutments  to  the  whalebone, 
or  is  similar  to  the  alveolar  processes  of  the  teeth,  keeping  them 
firm  in  their  places. 

As  both  the  whalebone  and  intermediate  substance  are'  con- 
stantly growing,  and  as  we  must  suppose  a determined  length 
necessary,  a regular  mode  of  decay  must  be  established,  not  de- 
pending entirely  on  chance  or  the  use  it  is  put  to. 

In  its  growth  three  parts  appear  to  be  formed  : one  from  the 
rising  core,  which  is  the  centre;  a second  on  the  outside;  and  a 
third, being  the  intermediate  substance.  These  appear  to  have  three 
stages  of  duration;  for  that  which  forms  on  the  core  I believe 
makes  the  hair,  and  that  on  the  outside  makes  principally  the  plate 
of  whalebone;  tliis,  when  got  a certain  length,  breaks  off,  leaving 
the  hair  projecting,  becoming  at  the  tenriination  very  brittle;  and 
the  third,  or  intermediate  substance,  by  the  time  it  rises  as  high  as 
the  edge  of  the  skin  of  the  jaw,  decays  and  softens  away  like  the 
old  cuticle  of  the  sole  of  the  foot  when  steeped  in  water.* 

The  use  of  the  whalebone,  I should  believe,  is  principally  for  the 
retention  of  the  food  till  swallowed,  and  do  suppose  the  fish  they 
catch  are  small  when  compared  with  the  size  of  the  mouth. 

The  oesophagus,  as  in  other  animals,  begins  at  the  fauces,  or  pos- 
terior part  of  the  mouth  ; and,  although  circular  at  this  part,  is  soon 
divided  into  two  passages  by  the  epiglottis  passing  across  it,  as  will 
be  described  hereafter.  Below  its  attachment  to  the  trachea,  it 
passes  down  in  the  posterior  mediastinum,  at  some  distance  from 
the  spine,  to  which  it  is  attached  by  a broad  part  of  the  same  mem- 
brane, and  its  anterior  surface  makes  the  posterior  part  of  the  cavity 
behind  the  pericardium. 

Passing  through  the  diaphragm  it  enters  the  stomach,  and  is  lined 
with  a very  tliick,  soft,  and  white  cuticle,  which  is  continued  into 
the  first  cavity  of  the  stomach. 

The  inner  or  true  coat  is  white,  of  a considerable  density,  and 
not  muscular,  but  thrown  into  large  longitudinal  folds  by  the  con- 
traction of  the  muscular  fibres  of  the  oesophagus,  which  are  very 
strong.  It  is  very  glandular  ; for  on  its  inner  surface,  especially 
near  the  fauces,  orifices  of  a vast  number  of  glands  are  visible. 

The  oesophagus  is  larger  in  proportion  to  the  bulk  of  the  animal 
than  in  tlie  quadruped,  although  not  so  much  so  as  it  usually  is  in 
fish,  wdiich  we  may  suppose  swallow  their  food  much  in  the  same 
way.  In  the  piked  whale  it  was  three  inches  and  a half  wide. 

* [The  supplementary  note  appended,  in  the  second  edition  of  the  ‘ Le9ons 
d’Anatomie  (Jomparee,’  tom.  iii.,  p.  376,  to  tiie  imperfect  description  given  by 
Cuvier  of  the  formation  of  the  whalebone,  is  a mere  condensation  of  the  minute, 
original,  and  accurate  account  in  the  text:  to  which,  however,  no  reference  is 
made  by  M,  Duvernoy.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC,  3r>9 

The  stomach,  as  in  other  animals,  lies  on  the  left  side  of  the  body, 
and  terminates  in  the  pylorus  towards  the  right. 

In  the  piked  whale  the  duodenum  passes  down  on  the  right  side, 
very  much  as  in  the  human  subject,  excepting  that  it  is  more  ex- 
posed, from  the  colon  not  crossing  it.  It  lies  on  the  right  kidney, 
and  then  passes  to  the  left  side  behind  the  ascending  part  of  the 
colon  and  root  of  the  mesentery,  comes  out  on  the  left  side,  and 
getting  on  the  edge  of  the  mesentery  becomes  a loose  intestine, 
forming  the  jejunum.  In  this  course  behind  the  mesentery  it  is  ex- 
posed, as  in  most  quadrupeds,  not  being  covered  by  it  as  in  the 
human.  The  jejunum  and  ileum  pass  along  the  edge  of  the  mesen- 
tery downwards  to  the  lower  part  of  the  abdomen.  The  ileum 
near  the  lower  end  makes  a turn  towards  the  right  side,  and  then 
mounting  upwards,  round  the  edge  of  the  mesentery,  passes  a little 
way  on  the  right,  as  high  as  the  kidney,  and  there  enters  the  colon 
or  csecum.  The  caecum  lies  on  the  lower  end  of  the  kidney,  con- 
siderably higher  than  in  the  human  body,  which  renders  the  ascend- 
ing part  of  the  colon  short.  The  caecum  is  about  seven  inches 
long,  and  more  like  that  of  the  lion  or  seal  than  of  any  other  animal 
I know. 

The  colon  passes  obliquely  up  the  right  side,  a little  towards  the 
middle  of  the  abdomen,  and  when  as  high  as  the  stomach  crosses 
to  the  left  and  acquires  a broad  mesocolon;  at  this  part  it  lies  upon 
the  left  kidney,  and  in  its  passage  down  gets  more  and  more  to  the 
middle  line  of  the  body.  When  it  has  reached  the  lower  part  of 
the  abdomen  it  passes  behind  the  uterus  and  along  with  the  vagina 
in  the  female,  between  the  two  testicles  and  behind  the  bladder  and 
root  of  the  penis  in  the  male,  bending  down  to  open  on  what  is 
called  the  belly  of  the  animal,  and  in  its  whole  course  it  is  gently 
convoluted.  In  those  which  have  no  caecum,  and  therefore  can 
hardly  be  said  to  have  a colon,  the  intestine  before  its  termination 
in  the  rectum  makes  the  same  kind  of  sweep  round  the  other  intes- 
tines as  the  colon  does  where  there  is  a cmcum. 

The  intestines  are  not  large  for  the  size  of  the  animal,  not  being 
larger  in  those  of  eighteen  or  twenty-four  feet  long  than  in  the 
horse,  the  colon  not  much  more  capacious  than  the  jejunum  and 
ileum,  and  very  short ; a circumstance  common  to  carnivorous 
animals.  In  the  piked  whale  the  length  from  the  stomach  to  the 
caecum  is  twenty-eight  yards  and  a lialf,  length  of  cscum  seven 
inches,  of  the  colon  to  the  anus  two  yards  and  three-quarters.  The 
small  intestines  are  just  five  times  the  length  of  the  animal,  the  colon 
with  the  caecum  a little  more  than  one-half  the  length. 

Those  parts  that  respect  the  nourishment  of  this  tribe  do  not  all  so 
exactly  correspond  as  in  land  animals,  for  in  these  one  in  some 
degree  leads  to  the  other.  Thus  the  teeth  in  the  ruminating  tribe 
point  out  the  kind  of  stomach,  caecum,  and  colon  ; while  in  others, 
as  the  horse,  hare,  lion,  &c.,  the  appearances  of  the  teeth  only  give 
us  the  kind  of  colon  and  caecum  ; but  in  this  tribe,  whether  teeth  or 
no  teeth,  the  stomachs  do  not  vary  much,  nor  does  the  circumstance 


360 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


of  cajcum  seem  to  depend  on  either  teetli  or  stomach.  The  circum- 
stances by  wliicli  from  the  form  of  one  part  we  judge  what  others 
are,  fail  us  liere : but  this  may  arise  from  not  knowing  all  the  cir- 
cumstances. The  stomach  in  all  that  I have  examined  consists  of 
several  bags  continued  from  the  first  on  the  left  towards  the  right, 
where  the  last  terminates  in  duodenum.  The  number  is  not  the 
same  in  all : for  in  the  porpoise,  grampus,  and  piked  whale  there 
are  five  ; in  the  bottle-nose  (Hyperoodon)  seven.  Their  size  res- 
pecting one  another  differs  very  considerably,  so  that  the  largest 
in  one  species  may  in  another  be  only  the  second.  The  two  first 
in  the  porpoise,  bottle-nose,  and  piked  whale  are  by  much  the  largest ; 
the  others  are  smaller,  although  irregularly  so. 

The  first  stomach  has,  I believe,  in  all  very  much  the  shape  of 
an  egg,  w'ith  the  small  end  downwards.  It  is  lined  everywhere 
with  a continuation  of  the  cuticle  from  the  oesophagus.  In  the  por- 
poise the  oesophagus  enters  the  superior  end  of  the  stomach.  In  the 
piked  whale  its  entrance  is  a little  way  on  the  posterior  part  of  the 
upper  end,  and  is  oblique. 

The  second  stomach  in  the  piked  whale  is  very  large,  and  rather 
longer  than  the  first.  It  is  of  the  shape  of  the  italic  S,  passing  out 
from  the  upper  end  of  the  first  on  its  right  side,  by  nearly  as  large 
a beginning  as  the  body  of  the  bag.  In  the  porpoise  it  by  no  means 
bears  the  same  proportion  to  the  first,  and  opens  by  a narrower 
orifice;  then  passing  down  along  the  right  side  of  the  first  stomach, 
it  bends  a little  outwards  at  the  lower  end,  and  terminates  in  the 
third.  Where  this  second  stomach  begins,  the  cuticle  of  the  first 
ends.*  The  whole  of  the  inside  of  this  stomach  is  throwm  into  un- 
equal rugm,  appearing  like  a large  irregular  honeycomb.  In  the 
piked  whale  the  rugae  are  longitudinal,  and  in  many  places  very 
deep,  some  of  them  being  united  by  cross  bands  ; and  in  the  por- 
poise the  folds  are  very  thick,  massy,  and  indented  into  one  another.! 
This  stomach  opens  into  the  third  by  a round  contracted  orifice, 
which  does  not  seem  to  be  valvular. 

The  third  stomach  is  by  much  the  smallest,  and  appears  to  be 
only  a passage  between  the  second  and  fourth.  It  has  no  peculiar 

* [The  lining  membrane  of  the  first  stomach  in  the  porpesse  sends  off  a number 
of  irregular  projections,  where  it  surrounds  the  opening  into  the  second  stomach, 
whereby  that  opening  is  rendered  valvular,  and  adapted  to  prevent  the  passage  of 
anything  but  fluids  or  substances  of  very  small  size.  'J’he  first  stomach,  there- 
fore, serves  not  only  as  a reservoir,  but  the  food  undergoes  a considerable  change 
in  it,  probably  by  the  action  of  the  gastric  secretion  of  the  second  cavity  regurgi- 
tated into  it.  Thus  the  bones  of  fish  have  been  found  in  the  first  cavity  with  all 
the  flesh  dissolved,  and  the  bones  ihemselves  softened  by  the  removal  of  their 
earthy  constituent.  See  Preparation  No.  569  o.  Physiological  Series,  Hunterian 
IMuseum.] 

t [It  is  to  this  stomach  that  the  pneumogastric  nerves  are  principally  distri- 
buted ; llie  thick  and  soft  lining  sulrstance  presents,  according  to  the  microsco- 
pical researches  of  Sir  David  Brewster,  a peculiar  structure,  consisting  of  closely 
aggregated  minute  tubes  placed  perpendicularly  between  the  smooth  internal 
mucous  membrane  and  the  vascular  tunic  which  immediately  lines  the  muscular 
coat.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


361 


structure  on  the  inside,  but  terminates  in  the  fourth  by  nearly  as 
large  an  opening  as  its  beginning.  In  the  porpoise  it  is  not  above 
one,  and  in  the  bottle-nose  about  five,  inches  long. 

The  fourth  stomach  is  of  a considerable  size ; but  a good  deal  less 
than  either  the  first  or  second.  In  the  piked  whale  it  is  not  round, 
but  seems  flattened  between  the  second  and  fifth.  In  the  porpoise 
it  is  long,  passing  in  a serpentine  course  almost  like  an  intestine. 
The  internal  surface  is  regular,  but  villous,  and  opens  on  its  right 
side  into  the  fifth  by  a round  opening  smaller  than  the  entrance 
from  the  third. 

The  fifth  stomach  is  in  the  piked  whale  round,  and  in  the  por- 
poise oval;*  it  is  small,  and  terminates  in  the  pylorus,  which  has 
little  of  a valvular  appearance.  Its  coats  are  thinner  than  those 
of  the  fourth,  having  an  even  inner  surface,  which  is  commonly 
tinged  with  bile. 

The  piked  whale,  and,  I believe,  the  large  whalebone  whale,  have 
a caecum  ; but  it  is  wanting  in  the  porpoise,  grampus,  and  bottle- 
nose  whale.f 

The  structure  of  the  inner  surface  of  the  intestine  is  in  some 
very  singular,  and  different  from  that  of  the  others. 

The  inner  surface  of  the  duodenum  in  the  piked  w'hale  is  thrown 
into  longitudinal  rugae,  or  valves,  w'hich  are  at  some  distance  from 
each  other,  and  these  receive  lateral  folds.  The  duodenum  in  the 
bottle-nose  swells  out  into  a large  cavity,  and  might  almost  be 
reckoned  an  eighth  stomach  ; but  as  the  gall-ducts  enter  it  I shall 
call  it  duodenum. 

The  inner  coat  of  the  jejunum,  and  ileum,  appears  in  irregular 
folds,  which  may  vary  according  as  the  muscular  coat  of  the  in- 
testine acts  : yet  I do  not  believe  that  their  form  depends  entirely 
on  that  circumstance,  as  they  run  longitudinally,  and  take  a ser- 
pentine course  when  the  gut  is  shortened  by  the  contraction  of  the 
longitudinal  muscular  fibres.  The  intestinal  canal  of  the  porpoise 
has  several  longitudinal  folds  of  the  inner  coat  passing  along  it 
through  the  whole  of  its  length.  In  the  bottle-nose  the  inner  coat, 
through  nearly  the  whole  track  of  the  intestine,  is  thrown  into  large 
cells,  and  these  again  subdivided  into  smaller ; the  axis  of  which 
cells  is  not  perpendicular  to  a transverse  section  of  the  intestine, 
but  oblique,  forming  pouches  with  the  mouths  downwards,  and  act- 
ing almost  like  valves  when  anything  is  attempted  to  be  passed  in 
a contrary  direction  ; they  begin  faintly  in  the  duodenum,  before 
it  makes  its  quick  turn,  and  terminate  near  the  anus.J  The  colon 

* [This  part  we  regard  as  the  dilated  duodenum,  since  the  gall-ducts  terminate 
in  it,  and  consequently  reckon  but  four  compartments  in  the  stomach  of  the  por- 
pesse.] 

t [In  all  the  vegetable  feeding  Cetacea  there  is  a caecum,  but  it  is  small.  In 
the  dugong  it  is  of  a simple  conical  form,  and  very  muscular.  In  the  manatee 
the  caecum  is  bifurcate.] 

4;  [See  the  Preparations,  Nos.  709,  710,  711,  712,  Physiological  Series,  Hun- 
terian Museum.] 


32 


362 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


and  rectum  have  the  rugae  very  flat,  which  seems  to  depend  entirely 
on  the  contraction  of  the  gut. 

The  rectum  in  the  piked  whale  near  the  anus,  appears  for  four 
or  five  inches  much  contracted,  is  glandular,  covered  by  a soft  cuticle, 
and  the  anus  small. 

I never  found  any  air  in  the  intestines  of  the  tribe;  nor  indeed  in 
any  of  the  aquatic  animals. 

The  mesenteric  artery  anastomoses  by  large  branches. 

There  is  a considerable  degree  of  uniformity  in  the  liver  of  this 
tribe  of  animals.  In  shape  it  nearly  resembles  the  human,  but  is 
not  so  thick  at  the  base,  nor  so  sharp  at  the  lower  edge,  and  is  pro- 
bably not  so  firm  in  its  texture.  The  right  lobe  is  the  largest  and 
thickest,  its  falciform  ligament  broad,  and  there  is  a large  fissure 
between  the  two  lobes,  in  w'hich  the  round  ligament  passes.  The 
liver  towards  the  left  is  very  much  attached  to  the  stomach,  the 
little  epiploon  being  a thick  substance.  There  is  no  gall-bladder. 
The  hepatic  duct  is  large,  and  enters  the  duodenum  about  seven 
inches  beyond  the  pylorus.* 

The  pancreas  is  a very  long,  fiat  body,  having  its  left  end  at- 
tached to  the  right  side  of  the  first  cavity  of  the  stomach  : it  passes 
across  the  spine  at  the  root  of  the  mesentery,  and  near  to  the  pylorus 
joins  the  hollow  curve  of  the  duodenum,  along  which  it  is  continued, 
and  adheres  to  that  intestine,  its  duct  entering  that  of  the  liver  near 
the  termination  in  the  gut. 

Although  this  tribe  cannot  be  said  to  ruminate,  yet  in  the  number 
of  stomachs  they  come  nearest  to  that  order  ; but  here  I suspect  that 
the  order  of  digestion  is  in  some  degree  inverted.  In  both  the  ru- 
minants, and  this  tribe,  I think  it  must  be  allowed  that  the  first 
stomach  is  a reservoir.  In  the  ruminants  the  precise  use  of  the 
second  and  third  stomachs  is  perhaps  not  known  ; but  digestion  is 
certainly  carried  on  in  the  fourth;  while  in  this  tribe,  I imagine, 
digestion  is  performed  in  the  second,!  and  the  use  of  the  third  and 
fourth  is  not  exactly  ascertained. 

The  caecum  and  colon  do  not  assist  in  pointing  out  the  nature  of 
the  food  and  mode  of  digestion  in  this  tribe.  The  porpoise,  which 
has  teeth  and  four  cavities  to  the  stomach,  has  no  caecum,  similar  to 
some  land  animals,  as  the  bear,  badger,  racoon,  ferret,  polecat,  &c. ; 
neither  has  the  bottle-nose  a caecum  which  has  only  two  small  teeth 
in  the  lower  jaw;  and  the  piked  whale,  which  has  no  teeth,  has  a 

* [In  the  dugong'  there  is  a gall-bladder  of  the  usual  dimensions,  which  is 
chiefly  peculiar  for  the  mode  in  which  the  bile  is  conveyed  to  it;  in  other  mam- 
malia this  takes  place  by  a communication  between  the  hepatic  and  cystic  ducts, 
at  some  distance  from  the  bladder,  but  here  two  large  hepatic  ducts  open  directly 
into  the  neck  of  the  gall-bladder,  in  the  same  way  as  the  ureters  terminate  in  the 
urinary  bladder.  The  cystic  duct,  which  fulfils  the  office  of  the  ductus  communis, 
proceeds  to  the  duodenum,  and  becomes  slightly  dilated,  before  it  enters  that  intes- 
tine. The  manatee  has  also  a gall-bladder,  but  it  is  wanting  in  the  northern 
manatee  or  Rytina.'] 

f [It  is  doubtless  performed  in  a great  part  by  the  secretion  of  the  second,  but 
as  before  observed,  the  act  is  far  advanced  in  the  first  cavity.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


363 


caecum,  almost  exactly  like  the  lion,  which  has  teeth  and  a very 
different  kind  of  stomach. 

The  food  of  the  whole  of  this  tribe,  I believe,  is  fish  ; probably 
each  may  have  a particular  kind  of  which  it  is  fondest,  yet  does  not 
refuse  a variety.  In  the  stomach  of  the  large  bottle-nose  I found 
the  beaks  of  some  hundreds  of  cuttle-fish.  In  the  grampus  I found 
the  tail  of  a porpoise;  so  that  they  eat  their  own  genus.  In  the 
stomach  of  the  piked  whale  I found  the  bones  of  different  fish,  but 
particularly  those  of  the  dog-fish.*  From  the  size  of  the  oesophagus 
we  may  conclude  that  they  do  not  swallow  fish  so  large  in  propor- 
tion to  their  size  as  many  fish  do  that  we  have  reason  to  be- 
lieve take  their  food  in  the  same  way ; for  fish  often  attempt  to 
swallow  what  is  larger  than  their  stomachs  can  at  one  time  contain, 
and  part  remains  in  the  oesophagus  till  the  rest  is  digested. 

The  epiploon  on  the  whole  is  a thin  membrane;  on  the  right 
side  it  is  rather  a thin  network, f though  on  the  left  it  is  a complete 
membrane,  and  near  to  the  stomach  of  the  same  side  becomes  of  a 
considerable  thickness,  especially  between  the  two  first  bags  of  the 
stomach.  It  has  little  or  no  fat,  except  what  slightly  covers  the 
vessels  in  particular  parts.  It  is  attached  forwards,  all  along  to 
the  lower  part  of  the  different  bags  constituting  the  stomach,  and 
on  the  right  to  the  root  of  the  mesentery  between  the  stomach  and 
transverse  arch  of  the  colon,  first  behind  to  the  transverse  arch  of 
the  colon  and  root  of  the  mesentery,  then  to  the  posterior  surface 
of  the  left  or  first  bag  of  the  stomach,  behind  the  anterior  attach- 
ment. In  some  of  this  tribe  there  is  the  usual  passage  behind  the 
vessels  going  to  the  liver,  common  to  all  quadrupeds  I am  acquaint- 
ed with  ; but  in  others,  as  the  small  bottle-nose,  there  is  no  such 
passage,  by  which  the  cavity  behind  the  stomach  in  the  epiploon 
of  this  animal  becomes  a circumscribed  cavity. 

The  spleen,  in  the  piked  whale,  is  involved  in  the  epiploon,  and  is 
very  small  for  the  size  of  the  animal.  There  are  in  some,  as  the 
porpoise,  one  or  two  small  ones,  about  the  size  of  a nutmeg,  often 
smaller,  placed  in  the  epiploon  behind  the  other.J  These  are  some- 
times met  with  likewise  in  the  human  body. 

The  kidneys  in  the  whole  of  this  tribe  of  animals  are  conglome- 
rated, being  made  up  of  smaller  parts,  which  are  only  connected  by 
cellular  membrane,  blood-vessels,  and  ducts,  or  infundibula  ; but  not 
partially  connected  by  continuity  of  substance,  as  in  the  human  body, 
the  ox,  &c. : every  portion  is  of  a conical  figure,  whose  apex  is 
placed  towards  the  centre  of  the  kidney,  the  base  making  the  ex- 
ternal surface ; and  each  is  composed  of  a cortical  and  tubular 
substance,  the  tubular  terminating  in  the  apex,  which  apex  makes 

* [In  the  stomach  of  the  porpesse  I have  found  the  bones  of  an  eel,  and  of  a 
flounder ; these  were  in  the  first  cavity.  The  great  sperm  whale  is  nourished 
principally  by  molluscaof  the  class  of  Cephalopods,  and  their  beaks  seem  to  form 
the  nuclei  of  the  intestinal  concretions,  called  ‘ ambergris.’] 

I [It  presents  this  reticulate  structure  in  the  otter.] 

X [The  smaller  accessory  spleens  are  sometimes  four,  five,  or  six  in  number.] 


364 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  mamilla.  Each  mamilla  has  an  infundibulum,  which  is  long, 
and  at  its  beginning  wide,  embracing  the  base  of  the  mamilla,  and 
becoming  smaller.  These  infundibula  unite  at  last,  and  form  the 
ureter.  The  whole  kidney  is  an  oblong,  flat  body,  broader  and 
thicker  at  the  upper  end  than  the  lower,  and  has  the  appearance  of 
being  made  up  of  different  parts  placed  close  together,  almost  like 
the  pavement  of  a street. 

The  ureter  comes  out  at  the  lower  end,  and  passes  along  to  the 
bladder,  which  it  enters  very  near  the  urethra. 

The  bladder  is  oblong,  and  small  for  the  size  of  the  animal. 

In  the  female  the  urethra  passes  along  to  the  external  sulcus  or 
vulva,  and  opens  just  under  the  clitoris,  much  as  in  the  human 
subject. 

Whether  being  inhabitants  of  the  water  makes  such  a construc- 
tion of  kidney  necessary  I cannot  say ; yet  one  must  suppose  it  to 
have  some  connection  with  such  situation,  since  we  find  it  almost 
uniformly  take  place  in  animals  inhabiting  the  water,  whether  wholly, 
as  this  tribe,  or  occasionally,  as  the  manatee,  seal,  and  white  bear: 
there  is,  however,  the  same  structure  in  the  black  bear,  which  I 
believe  never  inhabits  the  water.*  This,  perhaps,  should  be  con- 
sidered in  another  light,  as  Nature  keeping  up  to  a certain  unifor- 
mity in  the  structure  of  similar  animals  ; for  the  black  bear  in  con- 
struction of  parts  is,  in  every  other  respect  as  well  as  this,  like  the 
white  bear. 

The  capsulas  renales  are  small  for  the  size  of  the  animal,  when 
compared  to  the  human,  as  indeed  they  are  in  most  animals.  They 
are  flat,  and  of  an  oval  figure;  the  right  lies  on  the  lower  and  pos- 
terior part  of  the  diaphragm,  somewhat  higher  than  the  kidney ; the 
left  is  situated  lower  down,  by  the  side  of  the  aorta,  between  it  and 
the  left  kidney.  They  are  composed  of  two  substances,  the  external 
having  the  direction  of  its  fibres  or  parts  towards  the  centre;  the 
internal  seeming  more  uniform,  and  not  having  so  much  of  the 
fibrous  appearance. 

The  blood  of  animals  of  this  order  is,  I believe,  similar  to  that  of 
quadrupeds,  but  I have  an  idea  that  the  red  globules  are  in  larger 
proportion.  I will  not  pretend  to  determine  how  far  this  may 
assist  in  keeping  up  the  animal  heat,  but  as  these  animals  may  be 
said  to  live  in  a very  cold  climate  or  atmosphere,  and  such  as 
readily  carries  offbeat  from  the  body,  they  may  want  some  help  of 
this  kind. 

It  is  certain  that  the  quantity  of  blood  in  this  tribe  and  in  the 
seal  is  comparatively  larger  than  in  the  quadruped,  and  there- 
fore probably  amounts  to  more  than  that  of  any  other  known 
animal. 

* [In  the  heaver  and  other  Rodentia  of  amphibious  habits,  the  kidney  presents  . 
a simple  undivided  form  ; and  although  in  the  manatee  and  rytina  the  kidney 
presents  the  subdivided  type  of  formation,  yet  it  has  a smooth,  unbroken  external 
surface  in  the  dugong,  and  the  papillae  form  two  lateral  series  opening  into  a 
single  elongated  pelvis.] 


OBSERVATIONS  OF  THE  STRUCTURE,  ETC. 


365 


This  tribe  differs  from  fish  in  having  the  red  blood  carried  to  the 
extreme  parts  of  the  body,  similar  to  the  quadruped. 

The  cavity  of  the  thorax  is  composed  of  nearly  the  same  parts 
as  in  the  quadruped,  but  there  appears  to  be  some  difference,  and 
the  varieties  in  the  diffei'ent  genera  are  greater.  The  general 
cavity  is  divided  into  two,  as  in  the  quadruped,  by  the  heart  and 
mediastinum. 

The  heart  in  this  tribe  and  in  the  seal  is  probably  larger  in  pro- 
portion to  their  size  than  in  the  quadruped,  as  also  the  blood-vessels, 
more  especially  the  veins. 

The  heart  is  inclosed  in  its  pericardium,  which  is  attached  by  a 
broad  surface  to  the  diaphragm,  as  in  the  human  body.  It  is  com- 
posed of  four  cavities,*  two  auricles,  and  two  ventricles  : it  is  more 
flat  than  in  the  quadruped,  and  adapted  to  the  shape  of  the  chest. 
The  auricles  have  more  fasciculi,  and  these  pass  more  across  the 
cavity  from  side  to  side  than  in  many  other  animals  ; besides,  being 
very  muscular  they  are  very  elastic,  for  being  stretched  they  con- 
tract again  very  considerably.  There  is  nothing  uncommon  or 
particular  in  the  structure  of  the  ventricles,  in  the  valves  of  the 
ventricles,  or  in  that  of  the  arteries. 

The  general  structure  of  the  arteries  resembles  that  of  other 
animals,  and  where  parts  are  nearly  similar  the  distribution  is  like- 
wise similar.  The  aorta  forms  its  usual  curve,  and  sends  off  the 
carotid  and  subclavian  arteries.,f 

* As  the  circulation  is  a permanent  part  of  the  constitution  respecting  the  class 
to  which  the  animal  belongs,  and  as  the  kind  of  heart  corresponds  with  the  cir- 
culation, these  should  be  considered  in  the  classing  of  animals.  Thus  we  have 
animals  whose  hearts  have  only  one  cavity,  others  with  two,  three,  and  four 
cavities. 

t [Both  the  aorta  and  pulmonary  artery  are  considerably  dilated  above  their 
origin  in  the  narwhale,  according  to  Albers,  Mayer,  and  Rapp  (.Cetaceen,  p.  158,) 
In  the  porpoise  the  aorta  sends  off,  as  usual,  first  the  two  coronary  arteries,  then 
three  branches  from  the  convexity  of  the  arch.  The  first  of  these  is  the  largest ; 
it  sends  off  the  posterior  thoracic  and  then  the  right  carotid,  and  lastly,  divides  into 
therightsubclavianand  internal  mammary  arteries.  Thesecond  branch  sendsoffthe 
left  carotid,  subclavian,  and  internal  mammary  arteries  ; but  the  left  posterior  tho- 
racic arises,  as  a third  branch,  immediately  from  the  arcRof  the  aorta.  Notwith- 
standing the  shortness  of  the  neck,  the  common  carotid,  on  each  side,  sends  off  a 
branch,  as  in  most  mammalia,  before  dividing  into  the  external  and  internal 
carotids;  and  the  subordinate  branches  of  both  these  vessels  form  plexuses  in 
various  parts  of  the  head,  especially  at  the  basis  cranii,and  around  the  optic  nerve. 

The  abdominal  aorta  lies  deep  in  the  cleft  between  the  right  and  left  psoas 
muscles.  It  gives  off  the  ceeliac,  and  close  to  it  the  superior  mesenteric,  then,  at 
a greater  distance,  a small  inferior  mesenteric  artery;  also  a right  and  left  renal 
artery,  which,  in  the  true  Cetacea,  enter  the  upper  or  anterior  extremity  of 
the  kidney,  and  subdivides  to  distribute  branches  to  the  different  lobules,  like  the 
stalk  of  a bunch  of  grapes.  The  spermatic  arteries  are  quickly  resolved  into 
plexuses.  The  lumbar  arteries  are  given  off  as  usual  in  pairs  ; and  a little  ante- 
rior to  the  pelvic  bones  the  aorta  divides  into  two  hypogastric  arteries  (which 
send  off  the  umbilical  arteries  to  the  sides  of  the  bladder),  and  a middle  caudal 
artery,  which  is  the  largest,  and  passes,  as  a continuation  of  the  aortic  trunk, 
through  the  arches  of  the  inferior  spines.  There  are  no  branches  analogous  to 
common  iliac  and  crural  arteries.] 


32* 


366 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


Animals  of  this  tribe,  as  has  been  observed,  have  a greater  pro- 
portion of  blood  than  any  other  known,  and  there  are  many  arte- 
ries apparently  intended  as  reservoirs,  where  a larger  quantity  of 
arterial  blood  seemed  to  be  required  in  a part,  and  vascularity 
could  not  be  the  only  object.  Thus  we  find  that  the  intercostal 
arteries  divide  into  a vast  number  of  branches,  which  run  in  a ser- 
pentine course  between  the  pleura  and  the  ribs,  and  their  muscles, 
making  a thick  substance  somewhat  similar  to  that  formed  by  the 
spermatic  artery  in  the  bull.  Those  vessels  everywhere  lining  the 
sides  of  the  thorax  pass  in  between  the  ribs  near  their  articulation, 
and  also  behind  the  ligamentous  attachment  of  the  ribs,  and  anas- 
tomose with  each  other.  The  medulla  spinalis  is  surrounded  with 
a network  of  arteries  in  the  same  manner,  more  especially  where 
it  comes  out  from  the  brain,  where  a tliick  substance  is  formed  by 
their  ramifications  and  convolutions;  and  these  vessels  most  pro- 
bably anastomose  with  those  of  the  thorax.* 

The  subclavian  artery  in  the  piked  whale,  before  it  passes  over 
the  first  rib,  sends  down  into  the  chest  arteries  which  assist  in  form- 
ing the  plexus  on  the  inside  of  the  ribs;f  I am  not  certain  but  the 
internal  mammary  arteries  contribute  to  form  the  anterior  part  of 
this  plexus.  The  motion  of  the  blood  in  such  must  be  very  slow, 
the  use  of  which  we  do' not  readily  see. 

The  descending  aorta  sends  off'  the  intercostals,  wliich  are  very 
large,  and  give  branches  to  this  plexus;  and  when  it  has  reached 
the  abdomen,  it  sends  off,  as  in  the  quadruped,  the  different 

* [Tyson,  whowas  the  first  discoverer  and  describer  of  this  stmcture  (Anatomy 
of  a Porpesse,  p.  33,  pi,  2,  fior.  7,  4to.,  1680),  speaks  of  it  as  a ‘ glandulous  body,’ 
but  describes  it  as  a curious  contexture  of  blood-vessels  variously  contorted  and 
winding,  emerging  from  the  medulla  spinalis  at  the  holes  where  the  nerves  come 
out  between  the  ribs  ; and  he  observes,  “ the  same  substance  likewise  for  a good 
thickness  covered  the  medulla  sjiinalis  throughout.”  Hunter  first  determined 
the  exact  nature  of  this  structure,  and  that  it  was  a reservoir  of  arterial  blood. 
It  is  from  this  reservoir  that  the  central  axis  of  the  nervous  system  receives  its 
appropriate  stimulus,  and  the  powerful  muscles  of  the  tail  their  supply  of  oxy- 
genated blood  during  the  period  of  submersion  and  consequent  interruption  of  the 
respiratory  function.  M.  Breschet,  in  a treatise  ex  professo  on  this  structure, 
gives  some  beautiful  figures  of  it.  (See  Histoire  Jlnatomique  et  Fhysiologique  d'un 
Organs  dei  Nature  vasculaire  decouvert  dans  ks  Cetaces,  par  G.  M.  Breschet ; 4to. 
1836).  He  detected  it  in  the  Delpkinus  Delphis  and  Delphinus  Globiceps,  and  in 
a foetus  of  the  Balaena  Mysticelus  ,■  but  in  reasoning  on  the  physiology  of  the 
great  arterial  reservoirs  which  thus  seem  to  be  common  to  the  true  Cetacea,  it  is 
necessary  to  bear  in  mind  that  the  structure  does  not  exist  in  the  herbivorous 
Cetacea.] 

f [It  also  gives  off  external  thoracics  to  the  pectoral  muscles,  a subscapular 
branch,  and  one  to  the  supraspinal  fossa  : these  arteries  supply  the  moving  powers 
of  the  fin;  the  trunk  then  divides  in  two  branches,  which  almost  immediately 
subdivide,  and  form  plexuses  upon  the  humerus,  which  are  expended  in  nour- 
ishing the  bones  and  their  ligaments  and  the  enveloping  integument.  This  dis- 
position is  but  remotely  analogous  to  the  condition  of  the  axillary  artery  in  the 
slow  lemurs  and  sloth,  ’"here  a plexus  is  formed  by  a sudden  subdivision  of  the 
trun'K  into  numerous  small  branches,  w’hich  after  a brief  course  reunite  into  the 
common  trunk,  which  then  proceeds,  as  brachial  artery,  to  supply  the  muscles  of 
the  forearm  and  hand.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


367 


branches  to  the  viscera  and  the  lumbar  arteries,  which  are  like- 
wise very  large  for  the  supply  of  that  vast  mass  of  muscles  which 
moves  the  tail. 

In  our  examination  of  particular  parts,  the  size  of  which  is  gener- 
ally regulated  by  that  of  the  whole  animal,  if  we  have  only  been 
accustomed  to  see  them  in  those  which  are  small  or  middle-sized, 
we  behold  them  with  astonishment  in  animals  so  far  exceeding  the 
common  bulk  as  the  whale.  Thus  the  heart  and  aorta  of  the 
spermaceti  whale  appeared  prodigious,  being  too  large  to  be  con- 
tained in  a wide  tub,  the  aorta  measuring  a foot  in  diameter. 
When  we  consider  these  as  applied  to  the  circulation,  and  figure 
to  ourselves  that  probably  ten  or  fifteen  gallons  of  blood  are  thrown 
out  at  one  stroke,  and  moved  with  an  immense  velocity  through  a 
tube  of  a foot  diameter,  the  whole  idea  fills  the  mind  with  wonder. 

The  veins,  I believe,  have  nothing  particular  in  their  structure, 
excepting  in  parts  requiring  a peculiarity,  as  in  the  folds  of  the 
skin  on  the  breast  in  the  piked  whale,  w'here  their  elasticity  was  to 
be  increased.* 

Of  the  Larynx. 

The  larynx  in  most  animals  living  on  land  is  a compound  organ, 
adapted  both  for  respiration,  deglutition,  and  sound,  which  last  is 
produced  in  the  actions  of  respiration;  but  in  this  tribe  the  larynx 
I suppose  is  only  adapted  to  respiration,  as  w'e  do  not  know  that 
they  have  any  mode  of  producing  sound.t 

It  is  composed  of  os  hyoides,  thyroid,  cricoid,  and  tw'o  arytenoid 
cartilages,  with  the  epiglottis.  It  varies  very  much  in  structure 
and  size,  when  compared  in  animals  of  different  genera.  These 
cartilages  were  much  smaller  in  the  bottle-nose  of  twenty-four  feet 

* [Hunter  has  previously  noticed  the  great  capacity  of  the  veins  ; they  are 
also  remarkable  for  their  number  and  the  immense  plexuses  which  they  form 
in  different  parts  of  the  body,  but  above  all  for  the  almost  total  absence  of  valves. 
Tyson  has  given  a figure  of  the  extensive  venous  plexus  situated  on  the  mem- 
brane investing  the  psoas  muscles  (ibid.,  pi.  1,  fig.  2,  H.),  and  these  have 
recently  occupied  the  attention  of  Breschet,  loc,  cit.,  and  V.  Baer  (Jlcta  .dead. 
Nat.  Cur.,  vol.  xvii.,  p.  1,  1834).  The  inferior  and  superior  ven®  cav®  are  not 
brought  into  communication  by  the  vena  azygos,  as  in  other  mammalia;  such 
veins  in  the  usual  situation  in  the  chest  would  have  been  subject  to  compression 
between  the  arterial  plexuses  and  the  lungs.  The  ven®  azygos  are  therefore 
represented  by  two  venous  trunks  situated  in  the  interior  of  the  vertebral  canal, 
where  they  receive  the  intercostal  and  lumbar  veins,  and  finally  communicate 
with  the  superior  cava  by  means  of  a short  single  large  trunk,  which  penetrates 
the  parietes  of  the  posterior  and  right  side  of  the  chest.  The  non-valvular 
structure  of  the  veins  in  the  Cetacea,  and  the  pressure  of  the  sea-water  at  the 
depths  to  which  they  retreat  when  harpooned,  explain  the  profuse  and  deadly 
hemorrhage  which  follows  a wound  that  in  other  mammalia  would  be  by  no 
means  fatal.] 

f [My  learned  friend  and  colleague  in  the  present  work,  Mr.  T.  Bell,  considers 
the  evidence  to  be  strong,  if  not  incontestable,  in  favour  of  the  existence  of  a 
voice  in  the  Cetacea.  It  is  variously  decribed  as  a bellow,  a grunt,  or  a melan- 
choly cry  ; of  which  he  cites  several  instances  in  his  beautiful  work  on  British 
quadrupeds,  pp.  460,  475.] 


S68 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


long  than  in  the  piked  whale  seventeen  feet,  while  the  os  hyoides 
was  much  larger. 

In  the  bottle-nose  the  os  hyoides  is  composed  of  three  bones, 
besides  two  whose  ends  are  attached  to  it,  being  placed  above  the 
os  hyoides,  making  five  in  all.  In  the  porpoise,  piked  whale,  &c., 
it  is  but  one  bone,  slightly  bent,  having  a broad  thin  process  passing 
up,  which  is  a little  forked:  it  has  no  attachment  to  the  head  by 
means  of  other  bones,  as  in  many  quadrupeds. 

The  thyroid  cartilage  in  the  piked  whale  is  broad  from  side  to 
side,  but  not  from  the  upper  to  the  lower  part:  it  has  two  lateral 
processes,  which  are  long,  and  pass  down  the  outside  of  the 
cricoid,  near  to  its  lower  end,  and  are  joined  to  it  much  as  in  the 
human  subject.  These  difler  in  shape  in  diflferent  animals  of  this 
tribe. 

The  cricoid  cartilage  is  broad  and  flat,  making  the  posterior  and 
lateral  part  of  the  larynx,  and  is  much  deeper  behind,  and  laterally, 
than  before.  It  is  extremely  thick  and  strong,  flattened  on  the  pos- 
terior surface,  and  hollowed  from  the  upper  edge  to  the  lower.  It 
terminates  by  a thick  edge  on  the  posterior  part  above,  but  irregu- 
larly at  the  lower  edge,  in  the  cartilages  of  the  larynx. 

The  two  arytenoid  cartilages  are  extremely  projecting,  and 
united  to  each  other  till  near  their  ends  ; are  articulated  on  the 
upper  edge  of  the  cricoid,  but  send  down  a process,  which  passes 
on  the  inside  of  the  cricoid,  being  attached  to  a bag  in  the  piked 
whale,  which  is  formed  below  the  thyroid  and  before  the  cricoid 
cartilages  ; they  cross  the  cavity  of  the  larynx  obliquely,  making  the 
passage  at  the  upper  part  a groove  between  them  : the  cavity  at 
this  place  swells  out  laterally,  but  is  very  narrow  between  the  ante- 
rior and  posterior  surfaces.  The  passage  above  between  the 
arytenoid  and  thyroid  cartilages  is  wide  from  side  to  side,  and  is 
continued  down  on  the  outside  of  the  processes  of  the  arytenoid 
cartilage,  as  well  as  between  them,  ending  below  the  thyroid, 
which  is  foIlicLilated  on  its  inner  surface  on  the  fore  part  of  the  cri- 
coid cartilage. 

The  epiglottis  makes  a third  part  of  the  passage,  and  completes 
the  glottis  by  forming  it  into  a canal,  in  several  of  this  tribe;  but 
in  the  piked  whale  it  was  not  attached  to  the  two  arytenoid  car- 
tilages, but  only  in  contact,  or  inclosing  them  at  their  base,  so  as 
to  make  them  form  a complete  canal. 

I could  not  observe  anything  like  a thyroid  gland. ^ 

From  the  glottis  and  epiglottis  being  so  connected  as  to  make 
but  one  canal,  and  from  the  thyroid  and  cricoid  cartilages  being  so 
flattened  in  some  between  the  anterior  and  posterior  surface,  the 
passage  through  these  parts  is  very  small  or  contracted  ; but  the 
trachea  swells  out  again  into  a very  considerable  size.  Its  larger 
branches  are  in  proportion  to  the  trunk,  and  enter  the  lungs  at  the 
upper  end  along  with  the  blood-vessels. 

* [This  body  certainly  exists  both  in  the  porpoise  and  bottle-nose  dolphin  ; it 
is  bilobed,  and  placed  transversely  across  the  trachea.  Below  this  body  is  the 
tliymus,  which  extends  into  the  chest  and  is  much  subdivided.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


369 


Of  the  Lungs. 

The  lungs  are  two  oblong  bodies,  one  on  each  side  of  the  chest, 
and  are  not  divided  into  smaller  lobes,  as  in  the  humam  subject. 
They  are  of  considerable  length,  but  not  so  deep  between  the  fore 
and  back  part  as  in  the  quadruped,  from  the  heart  being  broad,  tltit, 
and  of  itself  filling  up  the  fore  part  of  the  chest.  They  pass  further 
down  on  the  back  part  than  in  the  quadruped,  by  which  their  size 
is  increased,  and  rise  higher  up  in  the  chest  than  the  entrance  of 
the  vessels,  coming  to  a point  at  the  upper  end.  From  the  entrance 
of  the  vessels  they  are  connected  downwards,  along  their  whole 
inner  edge,  by  a strong  attachment  (in  which  there  are  in  some 
lymphatic  glands)  to  the  posterior  mediastinum.  The  lungs  are 
extremely  elastic  in  their  substance,  even  so  much  so  as  to  squeeze 
out  any  air  that  may  be  thrown  into  them,  and  to  become  almost 
at  once  a solid  mass,  having  a good  deal  the  appearance,  consistence, 
and  feel  of  an  ox’s  spleen.  The  branches  of  the  bronchise  which 
ramify  into  the  lungs  have  not  the  cartilages  flat,  but  rather  rounded ; 
a construction  which  admits  of  greater  motion  between  each.* 

The  pulmonary  cells  are  smaller  than  in  quadrupeds,  which  ifiay 
make  less  air  necessary,  and  they  communicate  with  each  other, 
which  those  of  the  quadruped  do  not;  for  by  blowing  into  one 
branch  of  the  trachea,  not  only  the  part  to  which  it  immediately 
goes,  but  the  whole  lungs  are  filled. 

As  the  ribs  in  this  tribe  do  not  completely  make  the  cavity  of 
the  thorax,  the  diaphragm  has  not  the  same  attachments  as  in  the 
quadruped,  but  is  connected  forwards  to  the  abdominal  muscles, 
which  are  very  strong,  being  a mixture  of  muscular  and  tendinous 
fibres. 

The  position  of  the  diaphragm  is  less  transverse  than  in  the 
quadruped,  passing  more  obliquely  backwards,  and  coming  very 
low  on  the  spine,  and  higher  up  before;  which  makes  the  chest 
longest  in  the  direction  of  the  animal  at  the  back,  and  gives  room 
for  the  lungs  to  be  continued  along  the  spine. 

The  parts  immediately  concerned  in  inspiration  are  extremely 
strong;  the  diaphragm  remarkably  so.  The  reason  of  this  must 
at  once  appear;  it  necessarily  requiring  great  force  to  expand  in  a 
dense  medium  like  water,  especially  too  when  the  vacuity  is  to  be 
filled  with  one  which  is  rarer,  and  is  to  water  a species  of  vacuum, 
the  pressure  being  much  greater  on  the  external  surface  than  the 
counter-pressure  from  within.  But  expiration  on  the  other  hand 
must  be  much  more  easily  performed  ; the  natural  elasticity  of  the 
parts  themselves,  w'ith  the  pressure  of  the  water  on  the  external 
surface  of  the  body,  being  greater  than  the  resistance  of  the  air 

* [The  cartilaginous  hoops  of  thebronchize  ar  continued  to  their  extreme  rami- 
fications. The  pleura  costalis  is  denser  and  stronger  in  the  porpoise  than  serous 
membranes  usually  are.] 


370 


HUNTER  ON  THE  ANIMAL  GECONOMY. 


within,  will  both  tend  to  produce  expiration  without  any  immediate 
action  of  the  muscles.* 

The  diaphragm,  in  these  animals,  appears  to  be  the  principal 
agent  in  inspiration  ; and  the  cavity  of  the  thorax  not  being  entirely 
surrounded  by  bony  ])arts,  is  of  course  less  easily  expanded,  and 
the  apparatus  for  its  expansion  in  all  directions,  as  in  the  quadruped, 
does  not  exist  hero. 

The  Bloiv-hole,  or  Passage  for  the  Air. 

As  the  nose  in  every  animal  that  breathes  air  is  a common  pas- 
sage for  the  air,  and  is  also  the  organ  of  smelling,  I shall  describe 
it  in  this  tribe  as  instrumental  to  both  these  purposes. 

There  is  a variety  in  some  species  of  this  animal  which  is,  I 
believe,  peculiar  to  this  order ; that  is,  the  want  of  the  sense  of 
smelling;  none  of  those  which  I have  yet  examined  having  that 
sense,  except  the  two  kinds  of  whalebone  whale:  such  of  course 
have  neither  the  olfactory  nerves,  nor  the  organ  ; therefore  in  them, 
the  nostrils  are  intended  merely  for  respiration  ; but  others  have  the 
organ  placed  in  this  passage  as  in  other  animals. 

The  membranous  portion  of  the  posterior  nostrils  is  one  canal ; 
but  when  in  the  bony  part,  in  most  of  them,  it  is  divided  into  two  ; 
the  spermaceti  whale,  however,  is  an  exception.  In  those  which 
have  it  divided,  it  is  in  some  continued  double  through  the  anterior 
soft  parts,  opening  by  two  orifices,  as  in  the  piked  whale;  but  in 
others,  it  unites  again  in  the  membranous  part,  making  externally 
only  one  orifice,  as  in  the  porpoise,  grampus,  and  bottle-nose.  At 
its  beginning  in  the  fauces,  it  is  a roundish  hole,  surrounded  by  a 
strong  sphincter  muscle,  for  grasping  the  epiglottis;  beyond  this, 
the  canal  becomes  larger,  and  opens  into  the  two  passages  in  the 
bones  of  the  head.  This  part  is  very  glandular,  being  full  of  folli- 
cles, whose  ducts  ramify  in  the  surrounding  substance,  which 
appears  fatty  and  muscular  like  the  root  of  the  tongue,  and  these 
ramifications  communicate  with  one  another,  and  contain  a viscid 
slime.  In  the  spermaceti  whale,  which  has  a single  canal,  it  is 
thrown  a little  to  the  left  side. 

After  these  canals  emerge  from  the  bones  near  the  external 
opening,  they  become  irregular,  and  have  several  sulci  passing  out 
laterally,  of  irregular  forms,  with  corresponding  eminences.  The 
structure  of  these  eminences  is  muscular  and  fatty,  but  less  mus- 
cular than  the  tongue  of  a quadruped. 

In  the  porpoise  there  are  two  sulci  on  each  side  ; two  large  and 
two  small,  with  corresponding  eminences  of  different  shapes,  the 
large  ones  being  thrown  into  folds. 

The  spermaceti  whale  has  the  least  of  this  structure;  the  ex- 
ternal opening  in  it  comes  further  forwards  towards  the  anterior 

* [Professor  Mayer,  of  Bonn,  has  however  recently  described  a muscular  mem- 
brane as  immediately  investing  the  lungs  in  the  dolphin.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


371 


part  of  the  head,  and  is  consequently  longer  than  in  others  of  this 
order.  Near  to  its  opening  externally,  it  forms  a large  sulcus,  and 
on  each  side  of  this  canal  is  a cartilage,  which  runs  nearly  its 
whole  length.  In  all  that  I have  examined,  this  canal,  fonvards 
from  the  bones,  is  entirely  lined  with  a thick  cuticle  of  a dark  colour. 

In  those  w'hich  have  only  one  external  opening,  it  is  transverse, 
as  in  the  porpoise,  grampus,  bottle-nose  and  spermaceti  whale,  &c. ; 
where  double,  they  are  longitudinal,  as  in  the  piked  whale,  and 
the  large  whalebone  whale.  These  openings  form  a passage  for 
the  air  in  respiration  to  and  from  the  lungs  : for  it  would  be  impos- 
sible for  these  animals  to  breathe  air  through  the  mouth ; indeed,  I 
believe  the  human  species  alone  breathe  by  the  mouth,  and  in  them 
it  is  mostly  from  habit ; for  in  quadrupeds  the  epiglottis  conducts  the 
air  into  the  nose. 

In  the  whole  of  this  tribe,  the  situation  of  the  opening  on  the 
upper  surface  of  the  head  is  well  adapted  for  this  purpose,  being 
the  first  part  that  comes  to  the  surface  of  the  water  in  the  natural 
progressive  motion  of  the  animal  ; therefore  it  is  to  be  considered 
principally  as  a respiratory  organ,  and  where  it  contains  the  organ 
of  smell,  that  is  only  secondary. 

As  the  animals  of  this  order  do  not  live  in  the  medium  which 
they  inspire,  the  organs  conducting  the  air  to  the  lungs  are  in  some 
sort  particularly  constructed,  that  the  water  in  which  they  live  may 
not  interfere  with  the  air  they  breathe. 

The  projecting  glottis,  which  has  been  described,  passes  into  the 
posterior  nostrils,  by  which  means  it  crosses  the  fauces,  dividing 
them  into  two  passages.  The  enlargement  of  the  termination  of 
the  glottis,  observed  in  some  of  them,  would  seem  to  be  intended  to 
prevent  its  retraction ; but,  as  it  seems  confined  to  the  porpoise  and 
grampus,  it  may,  perhaps,  in  them  answer  some  other  purpose. 

The  beginning  of  the  posterior  nostrils,  which  answers  to  the  pala- 
tum molle  in  the  quadruped,  having  a sphincter,  the  glottis  is 
grasped  by  it,  which  renders  its  situation  still  more  secure,  and  the 
passages  through  the  head,  across  the  fauces  and  along  the  trachea, 
are  rendered  one  continued  canal;  this  union  of  glottis  and  epi- 
glottis with  the  posterior  nostril,  making  only  a kind  of  joint,  admits 
of  motion,  and  of  dilatation  and  contraction  of  the  fauces,  in  deglu- 
tition, from  the  epiglottis  moving  more  in  or  out  of  the  posterior 
nostril. 

This  construction  of  parts  answers  a purpose  similar  to  that  of 
the  epiglottis  in  the  quadruped  ; it  may  be  considered  as  the  epi- 
glottis and  the  arytenoid  cartilages  joining  to  make  a tubular  or 
cylindrical  epiglottis,  instead  of  a valvular  one. 

The  reasons  why  there  should  be  so  peculiar  a construction  of 
parts  do  not  at  first  appear ; but  we  certainly  see  by  it  an  absolute 
guard  placed  upon  the  lungs,  that  no  water  should  get  into  them. 

This  tribe  being  without  the  projecting  tongue  of  the  quadruped, 
and  wanting  its  extensive  motion  and  the  power  of  sucking  things 
into  the  mouth,  may  probably  require  the  construction  between  the 


372 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


air  and  lungs  to  be  more  perfect ; but  how  far  it  is  so  I will  not  pre- 
tend to  say. 

The  Brain  and  Medulla  Spinalis. 

The  size  of  the  brain  differs  much  in  different  genera  of  this 
tribe,  and  likewise  in  the  proportion  it  bears  fo  the  bulk  of  the  ani- 
mal. In  the  porpoise,  I believe,  it  is  the  largest,  and  perhaps  in 
that  respect  comes  nearest  to  the  human. 

The  size  of  the  cerebellum  in  proportion  to  that  of  the  cerebrum 
is  smaller  in  the  human  subject  than  in  any  animal  with  which  I am 
acquainted.  In  many  quadrupeds,  as  the  horse,  cow,  &c.,  the  dis- 
proportion in  size  between  cerebellum  and  cerebrum  is  not  great, 
and  in  this  tribe  it  is  still  less  ; yet  not  so  small  as  in  the  bird,  &c. 

The  whole  brain  in  this  tribe  is  compact,  the  anterior  part  of  the 
cerebrum  not  projecting  so  far  forwards  as  in  either  the  quadruped 
or  in  the  human  subject;  neither  is  the  medulla  oblongata  so  promi- 
nent, but  flat,  lying  in  a kind  of  hollow  made  by  the  two  lobes  of 
the  cerebellum.* * * § 

The  brain  is  composed  of  cortical  and  medullary  substances,  very 
distinctly  marked  ; the  cortical  being  in  colour  like  the  tubular  sub- 
stance of  a kidney,  the  medullary  very  white.  These  substances 
are  nearly  in  the  same  proportion  as  in  the  human  brain.  The  two 
lateral  ventricles  are  large,  and  in  those  that  have  olfactory  nerves 
are  not  continued  into  them  as  in  many  quadrupeds  ; nor  do  they 
wind  so  much  outwards  as  in  the  human  subject,  but  pass  close 
round  the  posterior  ends  of  the  thalami  nervorum  opticorum.f 
The  thalami  themselves  are  large,  the  corpora  striata  small  ;J  the 
crura  of  the  fornix  aie  continued  along  the  windings  of  the  ven- 
tricles, much  as  in  the  human  subject.§  The  plexus  choroides  is  at- 
tached to  a strong  membrane  which  covers  the  thalami  nervorum 
opticorum,  and  passes  through  the  whole  course  of  the  ventricle, 
much  as  in  the  human  subject. [j 

* [The  most  characteristic  feature  of  the  brain  of  the  Cetacean  is  its  great 
breadth,  which  exceeds  its  length.  Each  hemisphere  is  divided  below  by  a 
Jissura  magna  into  an  anterior  and  middle  lobe,  which  extends  over  the  cerebel- 
lum, so  as  to  form  a posterior  lobe.] 

f [They  extend,  as  in  the  human  subject,  into  an  anterior,  descending,  and 
posterior  horn  ; but  the  latter  is  very  small.] 

f [The  smallness  of  size  of  these  parts,  and  the  shortness  of  the  anterior  lobes 
of  the  brain  are  in  relation  with  the  absence  of  olfactory  nerves.  The  corpora 
striata  are  brought  into  communication  with  each  other  by  an  anterior  com- 
missu  re.] 

§ [The  fornix  sends  down  two  slender  anterior  pillars  to  the  corpora  albicantia, 
and  is  continued  into  the  anterior  part  of  the  corpus  callosum  ; it  then  bends 
backwards  along  the  under  surface  of  the  corpus  callosum  and  above  the  thalami, 
and  its  posterior  crura  sink  down,  and  diverge  from  each  other  to  form  the  hip- 
pocampi.] 

II  [The  hemispheres  of  the  brain  are  united  by  a corpus  callosum,  chiefly 
remarkable  for  its  position,  being  much  inclined  downwards  and  forwards;  its 
size  is  large,  bearing  the  usual  ])roportion  to  that  of  the  hemispheres.  The  bige- 
minal bodies  are  large  ; the  anterior  pair  are  rounded  and  lie  close  together  ; the 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


373 


The  substance  of  the  brain  is  more  visibly  fibrous  than  I ever  saw 
it  in  any  other  animal,  the  fibres  passing  from  the  ventricles  as 
from  a centre  to  the  circumference,  which  fibrous  texture  is  also 
continued  through  the  cortical  substance.  The  whole  brain  in  the 
piked  whale  weighed  four  pounds  ten  ounces.* 

The  nerves  going  out  from  the  brain,  I believe,  are  similar  to 
those  of  the  quadruped,  except  in  the  want  of  the  olfactory  nerves 
in  the  genus  of  the  porpoise. 

The  medulla  spinalis  is  much  smaller  in  proportion  to  the  size  of 
the  body  than  in  the  human  species,  but  still  bears  some  proportion 
to  the  quantity  of  brain ; for  in  the  porpoise,  where  the  brain  is 
largest,  the  medulla  spinalis  is  largest;  j^et  this  did  not  hold  good  in 
the  spermaceti  whale,  the  size  of  the  medulla  spinalis  appearing  to 
be  proportionally  larger  than  the  brain,  which  was  small  when 
compared  to  the  size  of  the  animal.  It  has  a cortical  part  in  the 
centre,  and  terminates  about  the  twenty-fifth  vertebra,  beyond  which 
is  the  cauda  equina,  the  dura  mater  going  no  lower.  The  nerves 
which  go  off  from  the  medulla  spinalis  are  more  uniform  in  size 
than  in  the  quadruped,  there  being  no  such  inequality  of  parts,  nor 
any  extremities  to  be  supplied,  except  the  fins.f 
The  medulla  spinalis  is  more  fibrous  in  its  structure  than  in 
other  animals ; and  w’hen  an  attempt  is  made  to  break  it  longitu- 
dinally it  tears  with  a fibrous  appearance,  but  transversely  it  breaks 
irregularly.^ 

The  dura  mater  lines  the  skull,  and  forms  in  some  the  three  pro- 
cesses answerable  to  the  divisions  of  the  brain,  as  in  the  human 
subject;  but  in  others  this  is  bone.  Where  it  covers  the  medulla 
spinalis  it  differs  from  all  the  quadrupeds  I am  acquainted  with, 
inclosing  the  medulla  closely,  and  the  nerves  immediately  passing 
out  through  it  at  the  low’er  part,  as  they  do  at  the  upper,  so  that 
the  cauda  equina,  as  it  forms,  is  on  the  outside  of  the  dura  mater. 

posterior  are  oval,  and  are  separated  by  a depression  which  receives  the  anterior 
part  of  the  vermiform  process  of  the  cerebellum.  The  medulla  oblongata  is  cha- 
racterized by  the  absence  of  the  trapezoid  bodies,  in  which  respect  it  resembles 
that  in  the  human  subject  and  orang.  The  remarkable  number  and  depth  of  the 
cerebral  convolutions  have  been  noticed  by  Tyson  in  the  porpoise,  by  Scoresby 
in  the  whale,  and  by  Tiedemann  in  the  dolphin.] 

* [Scoresby  found  the  brain  of  the  mysticete  whale  ^Balssna  Mysticetus)  to 
weigh  three  pounds  twelve  ounces.  Tyson  found  the  brain  of  a porpoise,  which 
weighed  ninety-six  pounds  avoirdupoise,  to  weigh  sixteen  ounces  and  a half.  I 
found  the  weight  of  the  brain  of  an  adult  male  porpoise  to  be  one  pound  two 
ounces  and  three-quarters  avoirdupoise.] 

t [The  anterior  roots  of  the  spinal  nerves  are  the  largest : the  posterior  roots, 
after  piercing  the  dura  mater,  are  continued  for  a third  of  an  inch  before  the  gan- 
glion is  formed  upon  them,  in  the  dorsal  region;  and  the  separate  roots  are  pro- 
gressively longer  as  they  come  off  nearer  the  caudal  extremity  of  the  spinal 
chord.  In  the  porpoise,  from  which  the  above  decription  is  taken,  I counted 
forty-one  pairs  of  spinal  nerves : the  cervical  are  closely  approximated  in  conse 
quence  of  the  shortness  of  the  neck.] 

f:  [ 1 he  canal  continued  from  the  fourth  ventricle  is  persistent  in  the  anterior  part 
of  the  spinal  chord,  as  in  the  horse.] 


33 


374 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


The  Organs  of  Sense. 

As  the  organs  of  sense  are  variously  formed  in  different  animals, 
fitted  for  the  various  modes  of  impression  ; and  as  the  modes  are 
either  increased  or  varied,  according  to  circumstances  which  make 
no  part  of  the  sense  itself,  but  which  are  necessary  for  the  ceconomy 
of  the  animal,  we  find  the  senses  in  this  tribe  varied  in  their  con- 
struction, and  in  some  a sense  is  even  wholly  wanting. 

The  organs  of  sense  which  appear  to  be  adapted  to  every  mode 
of  life  are  those  of  touch  and  taste;  but  those  of  smell,  sight,  and 
hearing,  probably  require  to  be  varied  according  to  circumstances. 
Thus  smell  may  be  increased  by  a mode  of  impregnation,  hearing 
by  the  vibration  of  different  mediums,  and  sight  by  the  different 
powers  of  refraction  of  different  mediums;  therefore  as  animals 
are  intended  by  Nature  to  be  differently  circumstanced,  so  are  the 
senses  formed. 


Of  the  Sense  of  Touch. 

The  cutis  in  this  tribe  appears  in  general  particularly  well  calcu- 
lated for  sensation,  the  whole  surface  being  covered  with  villi, 
w'hich  are  so  many  vessels,  and  we  must  suppose  nerves.  Whether 
this  structure  is  only  necessary  for  acute  sensation,  or  whether  it  is 
necessary  for  common  sensation,  where  the  cuticle  is  thick  and 
consisting  of  many  layers,  I do  not  know.  We  may  observe  that 
where  it  is  necessary  the  sense  of  touch  should  be  accurate  the  villi 
are  usually  thick  and  long,  which  probably  is  necessary,  because  in 
most  parts  of  the  body,  where  the  more  acute  sensations  of  touch 
are  required,  such  parts  are  covered  by  a thick  cuticle.  Of  this  the 
ends  of  our  fingers,  toes,  and  the  foot  of  the  hoofed  animals,  are 
remarkable  examples. 

Whether  this  sense  is  more  acute  in  water,  I am  not  certain  ; 
but  should  imagine  it  is. 


Of  the  Sense  of  Taste. 

The  tongue,  which  is  the  organ  of  taste,  is  also  endowed  with 
the  sense  of  touch.  It  is  likewise  to  be  considered,  in  the  greatest 
number  of  animals,  as  an  instrument  for  mechanical  purposes  ; but 
probably  less  so  in  this  tribe  than  any  other.  However,  even  in 
these  it  must  have  been  formed  with  this  view,  since  merely  as  an 
organ  of  taste  it  would  only  have  required  surface,  yet  is  a pro- 
jecting body  endowed  with  motion.  In  some  it  is  better  adapted 
for  motion  than  in  others  ; and  I should  suppose  this  to  be  requisite, 
on  account  of  the  difference  in  the  mode  of  catching  the  food  and 
in  the  act  of  swallowing.  It  is  most  projecting  in  those  with 
teeth,  probably  for  the  better  conducting  the  food,  step  by  step,  to 
the  cesophagus ; whereas  it  does  not  seem  so  necessary  to  have  such 
management  of  the  tongue  in  those  which  have  no  teeth,  and 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


375 


catch  their  food  by  merely  opening  the  mouth  and  swimming 
upon  it,  or  by  having  their  prey  carried  in  by  the  water.  In  the 
porpoise  and  grampus  it  is  firm  in  texture,  composed  of  muscle 
and  fat,  being  pointed  and  serrated  on  its  edges,  like  that  of  the 
hog.* 

In  the  spermaceti  whale  the  tongue  was  almost  like  a feather- 
bed.! In  the  piked  whale  it  was  but  gently  raised,  hardly  having 
any  lateral  edges,  and  its  tip  projecting  but  little,  yet,  like  every 
other  tongue,  composed  of  muscle  and  fat.  The  extent  between 
the  two  jaw-bones  in  this  whale  was  very  considerable,  taking  in 
the  whole  width  of  the  head  or  upper  jaw,  and  of  course  including 
the  whalebone.  This  extent  of  surface  between  jaw  and  jaw,  having 
but  little  projection  of  tongue,  is  almost  flat  from  side  to  side,  is 
extremely  elastic  when  contracted,  and  throws  the  inner  membrane 
into  a vast  number  of  very  small  folds,  that  run  parallel  to  one 
another,  but  which  are  again  thrown  into  a close  serpentine  course 
by  the  elasticity  of  the  part  in  a contrary  direction.  From  the 
tongue  being  capable  of  but  little  motion,  there  is  only  a small  mass 
of  muscle  required ; and,  from  the  thinness  of  the  jaw-bone,  the 
distance  between  the  lower  surface  of  the  mouth  and  external  sur- 
face of  the  skin  is  but  small ; and  this  skin  being  ribbed  and  very 
elastic  is  capable  of  considerable  distention,  by  which  the  cavity  of 
the  mouth  can  be  enlarged. 

The  tongue  of  the  large  whalebone  whale,  I should  suppose, 
rose  in  the  mouth  considerably ; the  two  jaws  at  the  middle  being 
kept  at  Such  a distance  on  account  of  the  whalebone,  so  that  the 
space  between,  when  the  mouth  is  shut,  must  be  filled  up  by  the 
tongue. 

Of  the  Sense  of  Smelling. 

In  this  tribe  of  animals  there  is  something  very  remarkable  in 
what  relates  to  the  sense  of  smelling ; nor  have  I been  able  to  dis- 
cover the  particular  mode  by  which  it  is  performed. 

When  we  consider  these  animals  as  mammalia,  and  only  con- 
structed differently  in  external  form  for  progressive  motion  through 
water,  we  must  see  that  it  was  necessary  that  all  the  senses  should 
correspond  with  this  medium:  we  must  therefore  be  at  a loss  to 
conceive  how  they  smell,  since  we  may  observe  that  the  organ  for 
smelling  water,  as  in  fish,  is  very  different  from  that  formed  to  smell 
air;  and  as  we  must  suppose  this  tribe  are  only  to  smell  water, 
being  the  medium  in  which  such  odoriferous  particles  can  be  dif- 
fused, we  should  expect  their  organ  to  be  similar  to  that  of  fish; 
but  in  that  case  nature  would  have  been  obliged  to  have  attacked 
the  nose  of  a fish  to  an  animal  constructed  like  a quadruped ; and 

* [We  have  found  the  marginal  serration  of  the  tongue  of  the  hog  only  in  the 
fcetus  or  very  young  state.] 

t [It  is,  however,  of  much  smaller  size  in  this  species  than  in  the  whalebone 
whales.] 


376 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


it  is  contrary  to  the  laws  which  are  established  in  the  animal  crea- 
tion to  mix  parts  of  different  animals  together. 

In  many  of  this  tribe  there  is  no  organ  of  smell  at  all ; and  in 
those  which  have  such  an  organ,  it  is  not  that  of  a fish,  therefore 
probably  not  calculated  to  smell  water.  It  becomes  diflicult 
therefore  to  account  for  the  manner  in  which  such  animals  smell 
the  water;  and  why  the  others  should  not  have  had  such  an 
organ,*  which,  I believe,  is  peculiar  to  the  large  and  small  whale- 
bone whales. 

Although  it  is  not  the  external  air  which  they  inspire  that  pro- 
duces smell,  I believe  it  is  the  air  retained  in  the  nostril  out  of  the 
current  of  respiration,  which  by  being  impregnated  with  the  odori- 
ferous particles  contained  in  the  water  during  the  act  of  blowing,  is 
applied  to  the  organ  of  smell.  It  might  be  supposed  that  they  could 
smell  the  air  on  the  surface  of  the  water  by  every  inspiration,  as 
animals  do  on  land  ; and  probably  they  may  : but  this  will  not  give 
them  the  power  to  smell  the  odoriferous  particles  of  their  prey  in 
the  water  at  any  depth;  and  as  their  organ  is  not  fitted  to  be 
affected  by  the  application  of  water,  and  as  they  cannot  suck  water 
into  the  nostril  without  the  danger  of  its  passing  into  the  lungs,  it 
cannot  be  by  its  application  to  this  organ  that  they  are  enabled 
to  smell. 

Some  have  the  power  of  throwing  the  water  from  the  mouth 
through  the  nostril,  and  with  such  force  as  to  raise  it  thirty  feet 
high  : this  must  answer  some  important  purpose,  although  not  im- 
mediately evident  to  us. 

As  the  organ  appears  to  be  formed  to  smell  air  only,  and  as  I 
conceive  the  smelling  of  the  external  air  could  not  be  of  use  as  a 
sense,  I therefore  believe  that  they  do  not  smell  in  inspiration  ; yet 
let  us  consider  how  they  may  be  supposed  to  smell  the  odoriferous 
particles  of  the  water. 

The  organ  of  smell  is  out  of  the  direct  road  of  the  current  of  air 
in  inspiration  ; it  is  also  out  of  the  current  of  water  when  they 
spout ; may  we  not  suppose  tlien,that  this  sinus  contains  air,  and  as 
the  water  passes  in  the  act  of  throwing  it  out,  that  it  impregnates 
this  reservoir  of  air,  w'hich  immediately  affects  the  sense  of  smell? 
This  operation  is  probably  performed  in  the  time  of  expiration,  be- 
cause it  is  said  that  this  water  is  sometimes  very  oflensive;  but  all 
this  I only  give  as  conjecture. 

If  the  above  solution  is  just,  then  only  those  which  have  the  organ 
of  smell  can  spout,  a fact  worthy  of  inquiry. 

The  organ  of  smell  would  appear  to  be  less  necessary  in  these 
animals  than  in  those  which  live  in  air,  since  some  are  wholly  de- 
prived of  it;  and  the  organ  in  those  which  have  it  is  extremely 

* Is  the  mode  of  smelling  in  fish  similar  to  tasting  in  other  animals'?  Or  is  the 
air  contained  in  the  water  impregnated  with  the  odoriferons  parts,  and  this  airthe 
fish  smells  ? If  so,  it  is  somewhat  similar  to  the  breathing  of  fish,  it  not  being 
the  water  which  produces  the  effect  there,  but  the  air  contained  in  it.  This  I 
proved  by  experiments,  and  is  mentioned  by  Dr.  Priestly. 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


377 


small,  when  compared  with  that  of  other  animals,  as  well  as  the 
nerve  which  is  to  receive  the  impi’ession,  as  was  observed  above.* 

Of  the  Sense  of  Hearing. 

The  ear  is  constructed  much  upon  the  same  principle  as  in  the 
quadruped  ; but  as  it  differs  in  several  respects,  which  it  is  necessary 
to  particularize,  to  convey  a perfect  idea  of  it  the  whole  should  be 
described.  As  this  would  exceed  the  limits  of  this  paper,  I shall 
content  myself  with  a general  description,  taking  notice  of  those 
material  points  in  which  it  differs  from  that  of  the  quadruped. 

This  organ  consists  of  the  same  parts  as  in  the  quadruped ; an 
external  opening,  with  a membrana  tympani,  an  Eustachian  tube, 
a tympanum  with  its  processes,  and  the  small  bones.f  There  is  no 
external  projection  forming  a f^unnel,  but  merely  an  external  open- 
ing. VV e can  easily  assign  a reason  why  there  should  be  no  pro- 
jecting ear,  as  it  wmuld  interfere  wdth  progressive  motion ; but  the 
reason  wdiy  it  is  not  formed  as  in  birds,  is  not  so  evident ; whether 
the  percussions  of  water  could  be  collected  into  one  point  as  air,  I 
cannot  say.  The  tympanum  is  constructed  with  irregularities,  so 
much  like  those  of  an  external  ear,  that  I could  suppose  it  to  have 
a similar  effect. 

The  external  opening  begins  by  a small  hole,  scarcely  percepti- 

* [It  is  singular  that  Mr.  Hunter  should  not  have  added  a description  of  the 
organ,  the  function  of  which  is  the  subject  of  so  many  singular  and  original 
speculations  in  the  preceding  section. 

The  olfactory  nerve  in  the  whalebone  whale  [Balxna  Mysticetus)  is  solid,  as 
in  the  human  subject,  but  round,  about  half  an  inch  in  diameter  at  its  narrowest 
part,  and  gradually  swelling  into  a pyriform  bulbous  termination,  from  the  fundus 
of  which  the  divisions  of  the  nerve  pass  off  through  the  foramina  of  the  cribriform 
plate;  the  larger  of  these  foramina  are  from  one  to  two  lines  in  diameter,  about 
twenty  in  number,  and  placed  chiefly  around  the  circumference  of  the  cribriform 
plate  ; there  are  two  large  ones  in  the  centre  which  lead  to  the  root  of  the  middle 
spongy  bone.  The  lamella  itself  is  concave  towards  the  fossa  of  the  nerve. 

The  nerves  are  lodged  for  some  distance  in  a peculiar  cavity,  surrounded  by 
the  cancellous  diploe  of  the  skull,  leading  from  the  cranial  cavity  to  the  cribriform 
plate.  The  turbinated  bones  are  three  in  number,  but  are  none  of  them  distinct, 
merely  projections  from  the  side  of  the  nasal  cavity  into  its  area.  The  middle 
one  is  the  largest;  besides  its  lateral  adhesion,  it  is  attached  by  a narrow  pedicle 
to  the  cribriform  plate,  from  which  it  quickly  expands  into  a body  of  about  one 
and  a half  inch  in  diameter,  having  an  upper,  middle,  and  lower  protuberance 
separated  by  sinuosities;  but  the  bone  is  not  a convoluted  plate,  but  solid,  or 
having  its  substance  of  the  same  cellular  structure  as  the  surrounding  diploe. 
The  inferior  turbinated  process  is  a simple  elliptic  protuberance,  about  one  inch 
in  length  and  half  an  inch  in  width. 

The  olfactory  nerves  in  the  Balsenopiera'd.re  somewhat  larger  than  in  the  human 
subject;  they  are  of  a pulpy  texture,  yet  readily  divisible  into  fasciculi,  and 
terminate  in  a small  bulb  which  rests  on  the  cribriform  plate.  Treviranus  states 
that  olfactory  nerves,  hut  of  very  minute  size  do,  exist  in  the  porpoise;  and  V. 
Baer  describes  them  as  being  one-sixth  of  a line  in  diameter  in  the  Delphinus 
Delphi's.] 

f [The  internal  ear  or  labyrinth,  which  Hunter  afterwards  describes  as  ‘the 
immediate  organ,’  seems  to  have  been  accidentally  omitted  in  the  above  enume- 
ration.] 


33^^ 


378 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


ble,  situated  on  the  side  of  head  a little  behind  the  eye.*  It  is 
much  longer  than  in  other  animals,  in  consequence  of  the  size  of 
the  head  being  so  much  increased  beyond  the  cavity  that  contains 
the  brain.  It  passes  in  a serpentine  course,  at  first  horizontally, 
then  dovvnw'ards,  and  afterwards  horizontally  again,  to  the  mem- 
brana  tympani,  where  it  terminates.  In  its  whole  length  it  is 
composed  of  diflerent  cartilages,  which  are  irregular  and  united 
together  by  cellular  membrane,  so  as  to  admit  of  motion  and 
probably  of  lengthening  or  shortening,  as  the  animal  is  more  or  less 
fat. 

The  bony  part  of  the  organ  is  not  so  much  inclosed  in  the  bones 
of  tlie  skull  as  in  the  quadruped,  consisting  commonly  of  a distinct 
bone  or  bones,  closely  attached  to  the  skull,  but  in  general  readily 
to  be  separated  from  it  ;f  yet  in  some  it  sends  off,  from  the  posterior 
part,  processes  which  unite  with  the  skull.  It  varies  in  its  shape, 
and  is  composed  of  the  immediate  organ  and  the  tympanum. 

The  immediate  organ  is,  in  point  of  situation  to  that  of  the  tym- 
panum, supei'ior  and  internal,  as  in  the  quadruped,  The  tympanum 
is  open  at  the  anterior  end,  where  the  Eustachian  tube  begins. 

The  Eustachian  tube  opens  on  the  outside  of  the  upper  part  of 
the  fauces : in  some  higher  in  the  nose  than  others;  highest  I be- 
lieve in  the  porpoise.  From  the  cavity  of  the  tympanum  where 
it  is  rather  largest,  it  passes  forwards  and  inwards,  and  near  its 
termination  appears  very  much  fasciculated,  as  if  glandular.J 

The  Eustachian  tube  and  tympanum  communicate  with  several 
sinuses,  which,  passing  in  various  directions,  surround  the  bone  of 
the  ear.  Some  of  these  are  cellular,  siaiilar  to  the  cells  of  the  mas- 
toid process  in  the  human  subject,  although  not  bony.  There  is  a 
portion  of  this  cellular  structure  of  a particular  kind,  being  white, 
ligamentous,  and  each  part  rather  rounded  than  having  flat  sides.§ 

* [In  the  full-grown  spermaceti  whale  Mr.  F.  D.  Bennett  found  the  aperture 
of  the  meatus  auditorius  to  form  a narrow  longitudinal  fissure,  one  inch  in  length; 
it  admitted  w'ith  difficulty  the  extremity  of  the  index  finger.] 

f [Being  united  to  the  skull  by  fibrous  texture  only,  a structure  which  is 
peculiar  to  the  Cetacea,  but  not  universal  in  that  order.] 

p [The  Eustachian  tube  in  the  true  Cetacea  is  characterized  by  its  membranous 
structure  throughout ; its  parietes  are  nowhere  sujjported  by  cartilage,  nordoes  it 
traverse  any  bone.  In  the  porpesse  its  internal  surface  is  provided  with  many 
semilunar  valves,  the  free  margins  of  which  are  directed  towards  the  nasal  outlet 
of  the  tube.] 

§ These  communications  with  the  Eustachian  tube  may  be  compared  to  a large 
bag  on  the  bases  of  the  skull  of  the  horse  and  ass,  which  is  a lateral  swell  of 
the  membranous  part  of  the  tube,  and  when  distended  will  contain  nearly  a 
quart. a 

a [In  a beautiful  drawing  of  the  organ  of  hearing  in  the  porpoise,  recently 
published  by  the  College  of  Surgeons,  Hunter  gives  a view  of  part  of  the  sinuses 
which  communicate  with  the  tympanum  and  Eustachian  tube.  See  Physiologi- 
cal Catalogue  of  the  Hunterian  Collection,  voL  iii.,  pi.  xxxiv,  i.  k.  In  the  pre- 
paration (No.  1582)  the  sinuses  are  seen  to  contain  numerous  small  worms 
{Strongylus  minor),  Kuhn,  Mem.  du  Museum,  tom.  xviii.,  p.  363.  The  same  have 
been  observed  by  other  physiologists,  as  Klein,  Camper,  Albers,  and  Rudolphi, 
the  latter  of  whom  regards  them  as  a small  variety  of  the  Strongylus  injlexus.']. 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


379 


One  of  the  sinuses  passing  out  of  the  tympanum  close  to  the  mem- 
brana  tympani,  goes  a little  way  in  the  same  direction,  and  com- 
municates with  a number  of  cells. 

The  whole  function  of  the  Eustachian  tube  is  perhaps  not  known  ; 
but  it  is  evidently  a duct  from  the  cavity  of  the  ear,  or  a passage 
for  the  mucus  of  these  parts;  the  external  opening  having  a par- 
ticular form  would  incline  us  to  believe,  that  something  was  con- 
veyed to  the  tympanum. 

The  bony  part  of  the  organ  is  very  hard  and  brittle,  rendering  it  even 
difficult  to  be  cut  with  a saw  without  itschipping  into  pieces.  That  part 
which  contains  the  immediate  organ  is  by  much  the  hardest,  and 
has  a very  small  portion  of  animal  substance  in  it;  for  when  steep- 
ed in  an  acid,  what  remains  is  very  soft,  almost  like  a jelly,  and 
laminated.  The  bone  is  not  only  harder  in  its  substance  but  there 
is  on  the  whole  more  solid  bone  than  in  the  corresponding  parts 
of  quadrupeds,  it  being  thick  and  massy. 

The  part  containing  the  tympanum  is  a thin  bone,  coiled  upon 
itself,  attached  by  one  end  to  the  portion  which  contains  the  organ  ; 
and  this  attachment  in  some  is  by  close  contact  only,  as  in  the  nar- 
w'hale  ; in  others,  the  bones  run  into  one  another,  as  in  the  bottle- 
nose  and  piked  whales. 

The  concave  side  of  the  tympanum  is  turned  towards  the  organ> 
its  two  edges  being  close  to  it;  the  outer  is  irregular,  and  in  many 
only  in  contact,  as  in  the  porpoise  : while  in  others  the  union  is  by 
bony  continuity,  as  in  the  bottle-nose  whale,  leaving  a passage  on 
which  the  rnembrana  tympani  is  stretched,  and  another  opening, 
which  is  the  communication  with  the  sinuses. 

The  surface  of  the  bone  containing  the  immediate  organ  opposite 
to  the  mouth  of  the  tympanum  is  very  irregular,  having  a number 
of  eminences  and  cavities.  The  cavity  of  the  tympanum  is  lined 
with  a membrane,  which  also  covers  the  small  bones  with  their 
muscles,  and  appears  to  have  a thin  cuticle.  This  membrane  ren- 
ders the  bones,  muscles,  tendons,  &c.,  very  obscure,  which  are  seen 
distinctly  when  that  is  removed.  It  appears  to  be  a continuation 
of  the  periosteum,  and  the  only  uniting  substance  between  the  small 
bones.  Besides  the  general  lining,  there  is  a plexus  of  vessels, 
which  is  thin  and  rather  broad,  and  attached  by  one  edge,  the  rest 
being  loose  in  the  cavity  of  the  tympanum,  somewhat  like  the  plexus 
choroides  in  the  ventricles  of  the  brain.  The  cavity  we  may  sup- 
pose intended  to  increase  sound,  probably  by  the  vibration  of  the 
bone  ; and  from  its  particular  formation  we  can  easily  conceive, 
that  the  vibrations  are  conducted,  or  reflected,  towards  the  imme- 
diate organ,  it  being  in  some  degree  a substitute  for  the  external 
ear. 

The  external  opening  being  smaller  than  in  any  animals  of  the 
same  size,  the  rnembrana  tympani  is  nearly  in  the  same  proportion. 
In  the  bottle-nose  whale,  the  grampus,  and  porpoise,  it  is  smooth  and 
concave  externally,  but  of  a particular  construction  on  the  inner 
surface  ; for  a tendinous  process  passes  from  it  towards  the  malleus. 


380 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


converging  as  it  proceeds  from  the  membrane,  and  becoming  thin- 
ner till  its  insertion  into  that  bone.  I could  not  discover  whether 
it  had  any  muscular  fibres  which  could  affect  the  action  of  the 
malleus.  In  the  piked  whale,  the  termination  of  the  external  opening, 
instead  of  being  smooth  and  concave,  is  projecting,  and  returns 
back  into  the  meatus  for  above  an  inch  in  length,*  is  firm  in  texture, 
with  thick  coats,  is  hollow  on  its  inside,  and  its  mouth  communi- 
cating with  the  tympanum  ; one  side  being  fixed  to  the  malleus, 
similar  to  the  tendinous  process  which  goes  from  the  inside  of  the 
membrana  tympani  in  the  others. f 

A little  way  within  the  membrana  tympani,  are  placed  the  small 
bones,  which  are  three  in  number,  as  in  the  quadruped,  malleus, 
incus,  and  stapes  ; but  in  the  bottle-nose  whale  there  is  a fourth, 
placed  on  the  tendon  of  the  stapedius  muscle.  These  bones  are  as 
it  were  suspended  between  the  bone  of  the  tympanum  and  that  of 
the  immediate  organ. 

The  malleus  has  two  attachments,  besides  that  with  the  incus ; 
one  close  to  the  bone  of  the  tympanum,  which,  in  the  porpoise,  is 
only  by  contact,  but  in  others  by  a bony  union  ;J  the  other  attach- 
ment is  formed  by  the  tendon,  above  described,  being  united  to  the 
inner  surface  of  the  membrana  tympani.  Its  base  articulates  with 
the  incus. 

* [As  might  be  expected,  the  same  structure  exists  in  the  whalebone  whale 
{Balve.na  Mysticetus,  Linn.),  where,  according  to  Home,  the  membrana  tympani 
“ instead  of  being  concave,  as  in  other  animals,  towards  the  meatus  externus,  is 
convex  and  projects  nearly  an  inch  into  that  tube.”  Phil.  Trans.  1812,  p.  84.  In 
this  respect,  the  whalebone  whales  resemble  the  sloths,  the  turtle,  and  crocodile, 
and  in  fact  the  whole  series  of  air-breathing  oviparous  vertebrata,  which  have 
the  ear-drum  convex  externally.  In  the  dolphins  and  porpoises,  however,  as 
also  in  the  narvvhale,  the  membrana  tympani  is  concave  externally,  as  in  other 
Mammalia.] 

f [This  connexion  between  the  membrana  tympani  and  the  malleus  is  denied 
by  Sir  Everard  Home,  who  wrote  a paper  and  gave  two  plates  in  support  of  his 
opinion.  After  quoting  Mr.  Hunter’s  description,  he  says,  “ the  fact  is,  that 
there  is  no  connection  whatever  between  the  membrana  tympani  and  the  malleus 
and  adds,  that  “ this  circumstance  forms  the  great  peculiarity  in  the  organ  of 
hearing  in  this  s|)ecies  of  whale  {Balxna  Mysticetus,  Linn,).”  So  singular  an 
anomaly  as  the  absence  of  any  communication  between  the  membrana  tympani 
and  the  ossicula  auditus,  would,  independently  of  our  interest  in  the  character  of 
Hunter  as  an  accurate  observer,  have  induced  us  to  spare  no  pains  to  test  the 
conflicting  statements  with  the  facts  themselves.  It  fortunately  happens  that  the 
preparations  figured  by  Horne  are  preserved  (No.  1598  a.  Physiological  Series, 
Hunterian  Museum)  ; and  after  a careful  examination  of  them,  we  find  the  fol- 
lowing to  be  the  true  structure  of  the  parts  in  question.  The  membrane  marked 
c in  Home’s  figure  (Phil.  Trans.,  1812,  pi.  II.)  is  continuous  at  d with  e,  the 
convex  projection  of  the  membrana  tympani;  whereas,  the  edge  of  the  shadow 
is  so  strong  in  the  figure  as  to  cause  it  to  appear  as  if  c and  e were  separate  mem- 
branes, as  Home  describes  them  to  be:  they  are,  however,  parts  of  the  same 
membrana  tympani,  the  attachment  of  which  is  extended  inwards  beyond  the  cir- 
cumference of  the  termination  of  the  bony  meatus  auditorius.  The  triangular 
ligament  proceeding  from  the  handle  of  the  malleus,  and  which  is  common  to 
all  the  Cetacea,  is  attached  not  only  to  the  plane  portion  of  the  ear-drum,  but 
to  the  whole  of  one  side  of  the  convex  portion  which  projects  into  the  meatus,  and 
is  affected  by  every  motion  of  that  portion.] 

[The  malleus  is  ancbylosed  to  the  parietes  of  the  tympanum  in  the  dugong.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


381 


The  incus  is  attached  by  a small  process  to  the  tympanum,  and 
is  suspended  between  the  malleus  and  stapes.  The  process  by  which 
it  articulates  with  the  stapes  is  bent  towards  that  bone. 

The  stapes  stands  on  the  vestibulum,  by  a broad  oval  base.  In 
many  of  this  tribe,  the  opening  from  side  to  side  of  the  stapes  is  so 
small  as  hardly  to  giv^e  the  idea  of  a stirrup.* 

The  muscles  which  move  these  bones  are  two  in  number,  and 
tolerably  strong.  One  arises  from  that  projecting  part  of  the  tym- 
panum which  goes  to  form  the  Eustachian  tube,  and  running  back- 
wards is  inserted  into  a small  depression  on  the  anterior  part  of 
the  malleus.  The  use  of  this  muscle  seems  to  be  to  tighten  the 
membrana  tympani ; but  in  those  which  have  the  malleus  anchy- 
losed  with  the  tympanum,  we  can  hardly  conjecture  its  use.  The 
other  has  its  origin  from  the  inner  surface  of  the  tympanum,  and 
passing  backwards  is  inserted  into  the  stapes  by  a tendon,  in  which 
I found  a bone  in  the  large  bottle-nose.  This  muscle  gives  the 
stapes  a lateral  motion.  What  particular  use  in  hearing  may  be 
produced  by  the  action  of  these  muscles,  I will  not  pretend  to  say ; 
but  we  must  suppose,  whatever  motion  is  given  to  the  bones  must 
terminate  in  the  movement  of  the  stapes. 

The  immediate  oi'gan  of  hearing  is  contained  in  a round  bony 
process,  and  consists  of  the  cochlea  and  semicircular  canals,  which 
somewhat  resemble  the  quadruped ; but,  besides  the  two  spiral 
turns  of  the  cochlea,  there  is  a third,  which  makes  a ridge  wiihin 
that  continued  from  the  foramen  rotundum,  and  follows  the  turns 
of  the  canal. 

The  cochlea  is  much  larger,  when  compared  with  the  semicir- 
cular canals,  than  in  the  human  species  and  quadruped. 

We  may  reckon  two  passages  into  the  immediate  organ  of  hear- 
ing, the  foramen  rotundum,  and  foramen  ovale.  They  are  at  a 
greater  distance  than  in  the  quadruped.  The  foramen  rotundum 
is  placed  much  more  on  the  outer  surface  of  the  bone,  and  not  in 
the  cavity  of  the  bony  tympanum ; but  may  be  said  to  communi- 
cate with  the  suiTOunding  cellular  part  of  the  tympanum.  The 
foramen  rotundum,  which  is  the  beginning  of  one  of  these  turns 
(the  scala  cochleoe,  which  is  the  central  or  inner  canal),  appears  to 
be  only  one  end  of  a transverse  groove,  which  is  afterwards  closed 
in  the  middle,  forming  a canal  with  the  two  ends  open ; so  that 
this  foramen  appears  to  have  two  beginnings ; but  the  other  open- 
ing is  probably  only  a passage  for  blood-vessels  going  to  the 
cochlea. 

From  this  foramen  begins  the  inner  turn  of  the  cochlea,  which  is 
the  largest,  especially  at  its  beginning ; the  other  begins  from  the 
vestibulum.  The  cochlea  is  a spiral  canal  coiled  within  itself,  and 
divided  into  two  by  a thin  spiral  bony  plate,  which  is  completed  in 
the  recent  subject,  and  forms  two  perfect  canals. 

In  the  recent  subject,  the  foramen  rotundum  is  lined  with  the 


[In  the  Detphinus  Leucas,  the  stapes  is  imperforate,  as  in  the  walrus.] 


382 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


membrane  of  the  tympanum,  which  terminates  in  a blind  end,  form- 
ing a kind  of  inembrana  cochleae.  The  other  opening,  in  the 
recent  subject,  communicates  with  the  spiral  turn,  beyond  the  mem- 
branous termination  of  the  foramen  rotundum. 

The  foramen  ovale  has  a little  projection  inwards  all  around,  on 
which  the  stapes  stands : within  this  is  the  vestibulum,  which  is 
common  to  the  other  spiral  turn  of  the  cochlem,  and  the  semicircu- 
lar canals ; this  canal  of  the  cochlea  (scala  vestibuli)  passes  out 
first  in  a direction  contrary  to  its  general  course,  but  soon  makes 
a turn  into  the  spiral.  It  is  round,  and  not  merely  a division  of  the 
cochlea  into  two  by  a septum,* * * §  but  has  a membrane  of  its  own, 
which  is  attached  to  the  thin  bony  plate,  and  lines  that  part  of  the 
cochlea  in  such  a manner  as  to  retain  its  structure  when  the  bone 
is  removed.  The  cochlea  in  some  completes  one  turn  and  a half; 
in  others,  more.f  It  is  not  a spiral  on  a plane,  or  cylinder,  but  on 
a cone. 

I have  already  observed,  that  by  looking  in  at  the  foramen  rotun- 
dum, we  see  two  small  ridges  ; the  uppermost  is  the  swell  of  the 
canal  from  the  vestibulum  just  described  ; the  lower  ridge,  which  is 
also  a canal,  may  be  observed  just  to  pass  along  the  foramen  be- 
longing to  this  canal,  close  to  the  septum  between  the  two  ; a cir- 
cumstance, I believe,  peculiar  to  this  tribe.  Its  beginning  is  close 
to  the  vestibulum,  but  does  not  open  from  it,  and  passes  along  the 
first-described  spiral  turn  to  its  apex : w'hen  opened,  it  appears  to 
be  a canal  full  of  small  perforations,  probably  the  passages  of  the 
branches  from  the  auditory  nerve. 

This  bony  process  has  several  perforations  in  it;  one  of  them 
large,  for  the  passage  of  the  seventh  pair  of  nerves.  The  size  of 
the  portio  mollis,  before  its  entrance  into  the  organ,  is  very  large, J 
and  bears  no  proportion  to  that  which  enters.  The  passage  for 
this  nerve  is  very  wide,  and  seems  to  have  an  irregular  blind  coni- 
cal, and  somewhat  spiral,  termination ; its  being  spiral  arise  from 
the  closeness  to  the  point  of  the  cochlea. 

In  the  terminating  part  there  are  a number  of  perforations  into 
the  cochlea,  and  one  into  the  semicircular  canals, § which  afford  a 
passage  to  the  different  divisions  of  the  auditory  nerve.  There  is 
a considerable  foramen  in  its  anterior  side  near  the  bottom,  for  the 
passage  of  the  portio  dura,  and  which  is  continued  backward  to 
the  cavity  of  the  tympanum  near  the  stapes,  and  emerges  near  the 
posterior  and  upper  part  of  this  bone. 

* [i.  e.,  It  is  a cylindrical  canal,  not  semicylindrical  as  usual  in  quadrupeds.] 

f [In  the  porpesse,  the  number  of  g-yraiions  are  two  and  a half.  Rudolph!  de- 
scribes two  and  a half  gyrations  in  the  narwhale.  Rapp  describes  two  complete 
gyrations  in  the  Delphinus  Ddphis,  and  Pallas  the  same  number  in  the  Ddph. 
Leucas."] 

y [Tiedemann  particularly  notices  the  large  size  of  the  acoustic  nerve  in  the 
dolphin.] 

§ [The  semicircular  canals  are  chiefly  remarkable  for  their  small  proportional 
size;  they  were  overlooked  by  Camper  and  Pallas,  but  were  described  by  Com- 
paretti  two  years  later  than  Plunter,  in  his  “ Obsei'vatio7ies  anatomicee  de  Jhirdn- 
ierna,'"  Patavii,  1789.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


383 


Of  the  Organ  of  Seeing. 

The  eye  in  this  tribe  of  animals  is  constructed  upon  nearly  the 
same  principle  as  that  of  quadrupeds,  differing,  however,  in  some 
circumstances;  by  which  it  is  probably  better  adapted  to  see  in 
the  medium  through  which  the  light  is  to  pass.  It  is  upon  the 
whole  small  for  the  size  of  the  animal,*  which  would  lead  to  the 
supposition  that  their  locomotion  is  not  great ; for  I believe  animals 
that  swim  are  in  this  respect  similar  to  those  that  fly ; and  as  this 
tribe  come  to  the  surface  of  the  medium  in  which  they  live,  they 
may  be  considered  in  the  same  view  with  birds  which  soar  ; and 
we  find  birds  that  fly  to  great  heights,  and  move  through  a con- 
siderable space  in  search  of  food,  have  their  eyes  larger  in  propor- 
tion to  their  size. 

The  eyelids  have  but  little  motion,!  and  do  not  consist  of  loose 
cellular  membrane,  as  in  quadrupeds,  but  rather  of  the  common 
adipose  membrane  of  the  body ; the  connection,  however,  of  their 
circumference  with  the  common  integuments  is  loose,  the  cellular 
membrane  being  less  loaded  with  oil,  which  allows  of  a slight  fold 
being  made  upon  the  surrounding  parts  in  opening  the  eyelids. 
This  is  not  to  an  equal  degree  in  them  all,  being  less  so  in  the  por- 
poise than  in  the  piked  whale. 

The  tunica  conjunctiva,  where  it  is  reflected  from  the  eyelid  to 
the  eyeball,  is  perforated  all  round  by  small  orifices  of  the  ducts  of 
a circle  of  glandular  bodies  lying  behind  it. 

The  lachrymal  gland  is  small  its  use  being  supplied  by  those 
above  mentioned  ; and  the  secretion  from,  them  all  I believe  to  be 
a mucus  similar  to  what  is  found  in  the  turtle  and  crocodile.  There 
are  neither  puncta  nor  lachrymal  duct,  so  that  the  secretion,  what- 
ever it  may  be,  is  washed  off  into  the  water. 

The  muscles  which  open  the  eyelids  are  very  strong : they  take 
their  origin  from  the  head,  round  the  optic  nerve,  which  in  some 
requires  their  being  very  long,  and  are  so  broad  as  almost  to  make 
one  circular  muscle  round  the  whole  of  the  interior  straight  muscles  of 
the  eye  itself.  They  may  be  divided  into  four;  a superior,  an  in- 
ferior, and  one  at  each  angle  : as  they  pass  outwards  to  the  eyelids, 
they  diverge  and  become  broader,  and  are  inserted  into  the  inside 
of  the  eyelids  almost  equally  all  round.  They  may  be  termed  the 
dilatores  of  the  eyelids;  and,  before  they  reach  their  insertion, give 

* [The  longest  diameter  of  the  eye  of  the  mysticete  whale  and  of  the  cachalot 
is  two  inches  and  a half,  that  of  the  piked  whale  four  inches ; but  the  eye  owes 
much  of  its  bulk  to  the  thick  sclerotic.  An  affinity  to  the  elephant  and  other 
large  Pachyderms  is  manifested  in  this  circumstance.] 

I [The  true  Cetacea  have  no  tarsel  cartilages,  and  no  membrana  nictitans,  or 
third  eyelid  ; this  is  present  in  the  harbivorous  species,  as  the  dugong  and  ma- 
natee, and  is  represented  by  a thick  duplicature  of  the  conjunctiva  at  the  inner 
canthus  in  the  cachalot,] 

X [This  is  merely  a larger  development  of  the  palpebral  glands  at  the  inner 
side  of  the  eyeball,  and  should  therefore  be  regarded  as  analogous  to  a Harderian 
gland.] 


384 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


off  the  external  straight  muscles,  which  are  small,* * * §  and  inserted  into 
the  sclerotic  coat  before  the  transverse  axis  of  the  eye : those  may  be 
named  the  elevator,  depressor,  adductor,  and  abductor,  and  maybe  dis- 
sected away  from  the  others  as  distinct  muscles.  Besides  these  four 
going  from  the  muscles  of  the  eyelid  to  the  eye  itself,  there  are  two 
which  are  larger,  and  inclose  the  optic  nerve  with  the  plexus.  As 
these  pass  outwards  they  become  broad,  may  in  some  be  divided 
into  four,  and  are  inserted  into  the  sclerotic  coat,  almost  all  round 
the  eye,  rather  behind  its  transverse  axis.f 

The  two  oblique  muscles  are  very  long;  they  pass  through  the 
muscles  of  the  eyelids,  are  continued  on  to  the  globe  of  the  eye, 
between  the  two  sets  of  straight  muscles,  and  at  their  insertions  are 
very  broad  ; a circumstance  which  gives  great  variation  to  the 
motion  of  the  eye.J 

The  sclerotic  coat  gives  shape  to  the  eye,  both  externally  and 
internally,  as  in  other  animals;  but  the  external  shape  and  that  of 
the  internal  cavity  are  very  dissimilar,  arising  from  the  great  dif- 
ference in  the  thickness  of  this  coat  in  different  parts.  The  exter- 
nal figure  is  round,  except  that  it  is  a little  flattened  forwards;  but 
that  of  the  cavity  is  far  otherwise,  being  made  up  of  sections  of 
various  circles,  being  a little  lengthened  from  the  inner  side  to  the 
outer,  a transverse  section  making  a short  ellipsis. 

In  the  piked  whale  the  long  axis  is  two  inches  and  three-quarters, 
the  short  axis  two  inches  and  one-eighth. § 

The  posterior  part  of  the  cavity  is  a tolerably  regular  curve, 
answering  to  the  difference  in  the  two  axises;  but  forwards,  near 
the  cornea,  the  scleretic  coat  turns  quickly  in,  to  meet  the  cornea, 

* [The  word  “small”  is  here  used  relatively  to  the  palpebral  muscles ; for, 
compared  with  the  size  of  the  eyeball  the  recti  muscles  in  the  Cetacea  exceed  in 
bulk  those  of  any  other  mammiferous  animal.] 

f [These  shorter  series  of  straight  muscles  correspond  with  thechoanoid  mus- 
cle or  retractor  oculi  of  other  mammalia  in  which  (man  and  the  quadrumana 
excepted),  it  coexists  with  a membrana  nictitans,  and  is  subservient  to  its  mo- 
tions by  retracting  the  globe  of  the  eye  and  displacing  the  adipose  matter  pos- 
terior to  the  eyeball,  which  then  presses  forward  the  third  eyelid.  In  the  true 
Cetacea  where  there  is  no  third  eyelid  some  other  uses  must  be  assigned  for  the 
retractor  oculi ; it  may  perhaps  assist  by  retracting  the  eyeball,  in  closing  the 
ordinary  eyelids,  wliich  have  not  the  advantage  of  an  orbicularis  muscle  for  that 
purpose.  The  retractor  oculi  is  represented  by  four  short  muscles  in  the  turtle 
and  tortoise,  where  the  third  eyelid  is  present,  but  has  a special  muscle  for  nic- 
titation.] 

X [The  superior  oblique  arises,  as  in  other  mammalia,  from  the  posterior  part 
of  the  orbit  above  the  foramen  opticiim  ; it  passes  forwards  on  the  external  sur- 
face of  the  conical  apertor  palpebrarum,  which  it  perforates,  and  a kind  of  pulley 
is  formed  for  it  by  this  muscle  and  the  cellular  substance  beneath  it,  the  superior 
oblique  becoming  at  this  bend  partially  tendinous,  but  with  little  diminution  of 
size  ; it  then  goes  to  be  inserted  into  the  sclerotica,  at  such  a direction  to  the  ball 
of  the  eye  as  to  act  as  a rotator  to  it,  according  to  the  use  assigned  by  Hunter  to 
the  oblique  muscles  in  a previous  memoir.  The  inferior  oblique  arises  from  the 
superior  maxillary  bone  at  the  inner  side  of  the  orbital  space.  Neither  the  direc- 
tion of  this  or  of  the  superior  oblique  in  the  whales  enables  them  to  act  as  the  anta- 
gonists of  the  recti  muscles.] 

§ [See  a view  of  the  section  of  the  eye  of  a whale  in  Soemering’s  work,  enti- 
tled, “ De  Oculorum  sectione  horizontally  tab.  ii.] 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


385 


which  makes  this  part  of  the  cavity  extremely  flat,  and  renders 
the  distance  between  the  anterior  part  of  the  sclerotic  coat  and  the 
bottom  of  the  eye  not  above  an  inch  and  a quarter. 

In  the  piked  whale  the  sclerotic  coat,  at  its  posterior  part,  is  very 
thick : near  the  extreme  of  the  short  axis  it  was  half  an  inch,  and 
at  the  long  axis  one-eighth  of  an  inch  thick.  In  the  bottle-nose 
whale  [Hyperoodon)  the  extreme  of  the  short  axis  was  half  an  inch 
thick,  and  the  extremes  of  the  long  axis  about  a quarter  of  an  inch, 
or  half  the  other. 

The  sclerotic  coat  becomes  thinner  as  it  approaches  to  its  union 
with  the  cornea,  where  it  is  thin  and  soft.  It  is  extremely  firm  in 
its  texture  where  thick,  and  from  a transverse  section  would  seem 
to  be  composed  of  tendinous  fibres,  intermixed  with  something  like 
cartilage:  in  this  section  four  passages  for  vessels  remain  open. 
This  firmness  of  texture  precludes  all  effect  of  the  straight  muscles 
on  the  globe  of  the  eye,  by  altering  its  shape,  and  adapting  its  focus 
to  diflerent  distances  of  objects,  as  has  been  supposed  to  be  the 
case  in  the  human  eye. 

The  cornea  makes  rather  a longer  ellipsis  than  the  ball  of  the  eye  ; 
the  sides  of  which  are  not  equally  curved,  the  upper  being  most 
considerably  so.  It  is  a segment  of  a circle  somewhat  smaller 
than  that  of  the  eyeball,  is  soft  and  very  flaccid.* 

The  tunica  choroides  resembles  that  of  the  quadruped  ; and  its 
inner  surface  is  of  a silver  hue,  without  any  nigrum  pigmentum.-f 

The  nigrum  pigmentum  only  covers  the  ciliary  processes,  and 
lines  the  inside  of  the  iris.J 

* [In  the  preparation  No.  1682,  Physiological  Series,  Hunterian  Museum, 
Hunter  has  displayed  the  laminated  structure  of  the  cornea  of  the  whale;  this 
was  known  to  Leeuenhoek,  who  succeeded  in  separating  it  into  twenty-two 
layers.  See  Episl.  Phys.  p.  42,  which  are  united  by  a fine  cellular  tissue.] 

f [The  choroid  in  the  cetacea  is  easily  separable  into  two  vascular  laminae,  of 
which  the  outermost  is  of  a blackish  colour,  and  is  composed  of  larger  vessels, 
connected  by  cellular  membrane,  which  gives  it  a tomentose  appearance  ; the 
innermost  (raembrana  rhuischiana)  is  equally  vascular,  of  a pale  colour,  dense, 
but  thinner,  most  delicately  villousand  lined  by  a remarkable  tapetum  of  a bluish- 
white  colour  in  the  whale,  with  a greenish  and  somewhat  yellowish  tinge  in  the 
cachalot,  and  of  a very  light  blue  in  the  porpesse.  The  ciliary  zone  is  black, 
broad,  almost  flat,  composed  of  about  seventy  long  processes,  thick,  flexous, 
and  extending  their  cylindrical  apices  almost  as  far  as  the  anterior  surface  of  the 
lens.] 

k [When  this  layer  of  pigment  is  removed  from  the  iris,  (as  Hunter  has  done 
in  the  preparation  1680,  Physiological  Series,)  the  fibrous  structure  of  the  pos- 
terior part  of  the  iris  becomes  very  apparent;  the  outer  series  of  fibres  converge 
towards  the  margin  of  the  pupil,  where  they  are  concealed  by  the  sphincterfibres 
which  surround  that  part ; these  latter  elliptically  disposed  fibres  are  stronger  than 
the  radiated  ones.  The  posterior  fibrous  coat  of  the  iris  may  be  separated  without 
much  difficulty  from  the  anterior  vascular  layer.  This  consists  chiefly  of  the 
branches  of  the  two  long  ciliary  arteries,  which  bifurcate  opposite  the  long  axis 
of  the  pupil,  and,  the  opposite  branches  anastomosing,  form  a canal  which  sur- 
rounds the  pupil.  Numerous  tortuous  or  wavy  branches  radiate  from  this  canal 
towards  the  outer  margin  of  the  iris. 

In  the  preparations  No.  1680  and  1683  the  structure  of  the  iris  in  the  whale  is 
beautifully  shown. 

The  choroid  is  puckered  up  into  numerous  minute  folds,  which  form  the  ciliary 

34 


3S6 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


The  retina  appears  to  be  nearly  similar  to  that  of  the  quadruped. 

The  arteries  going  to  the  coats  of  the  eye  form  a plexus  passing 
round  the  optic  nerve,  resembling  in  its  appearance  that  of  the 
spermatic  artery  in  the  bull  and  some  other  animals.* 

The  crystalline  humour  resembles  that  of  the  quadruped ; but 
whether  it  is  very  convex  or  flattened  I cannot  determine,  those  I 
have  examined  having  been  kept  too  long  to  preserve  their  exact 
shape  and  size.f  The  vitreous  humour  adhered  to  the  retina  at  the 
entrance  of  the  optic  nerve. 

The  optic  nerve  is  very  long  in  some  species,  owing  to  the  vast 
width  of  the  head.J 

I shall  not  at  present  consider  the  eye  in  animals  of  this  tribe,  as 
it  respects  the  power  of  vision,  that  being  performed  on  a general 
principle  common  to  every  animal  inhabiting  the  water;  more 
especially  as  I am  only  master  of  the  construction  and  formation 
of  the  coats,  and  not  of  the  size,  shape,  and  densities  of  the  humours; 
yet  from  reasoning  we  must  suppose  them  to  correspond  with  the 
shape  of  the  eye,  and  the  medium  through  which  the  light  is  to 
pass. 

Of  the  Parts  of  Generation. 

The  parts  of  generation  in  both  sexes  of  this  order  of  animals 
come  nearer  in  form  to  those  of  the  ruminating  than  of  any  others, 
and  this  similarity  is,  perhaps,  more  remarkable  in  the  female  than 
in  the  male,  for  their  situation  in  the  male  must  vary  on  account 
of  external  form,  as  w'as  before  observed. 

The  testicles  retain  the  situation  in  which  they  were  formed,  as 
in  those  quadrupeds  in  which  they  never  come  down  into  the  scrcr- 
tum.§  They  are  situated  near  the  lower  part  of  the  abdomen,  one 
on  each  side,  upon  the  two  great  depressors  of  the  tail.  At  this 
part  of  the  abdomen  the  testicles  come  in  contact  with  the  abdomi- 
nal muscles  anteriorly.|| 

zone ; of  these  folds  every  third,  fourth,  or  fifth  becomes  enlarged,  and  is 
extended  forwards  in  the  form  of  a wrinkled  process  about  three  lines  in  length, 
compressed  laterally,  and  terminating  somewhat  obtusely  ; between  these  larger 
ciliary  processes,  which  are  about  seventy  in  number,  there  are  shorter  processes 
of  a similar  structure.] 

* [See  prep.  No.  1679,  Physiological  Series,  Hunterian  Museum.] 

t ['I'he  crystalline  lens  is  inclosed  in  a strong  capsule,  is  remarkably  globose, 
rather  more  flattened  anteriorly  than  posteriorly,  placed  at  a very  small  distance 
from  the  cornea,  and  accordingly  diminishing  the  space  for  the  aqueous,  while 
it  increases  that  for  the  vitreous  humour.  In  the  preparations  of  the  crystalline 
lens  in  the  Hunterian  Museum,  preps.  Nos.  1658-1687,  the  nucleus  is  seen 
to  be  excentric,  and  situated  on  the  posterior  half  of  the  lens,  and  is  of  a dark 
colour.] 

[When  this  nerve  is  divided  transversely,  and  the  medullary  substance 
squeezed  out,  the  neurilema  does  not  present  the  form  of  tubes,  but  of  numerous 
septa,  which  converge  from  the  circumference  to  the  centre  of  the  nerve.] 

§ [In  this  respect  however  the  cetacea  differ  from  the  ruminants,  and  resemble 
the  elephant  and  the  hyrax  amongst  the  pachyderms.] 

II  [At  the  period  of  sexual  excitement  the  testes  acquire  a great  size.  In  a 
Hiale  porpoise  1 found  them  occupying  almost  entirely  the  posterior  fourth  part  of 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


387 


The  vasa  deferentla  pass  directly  from  the  epididymis  behind  the 
bladder,  or  between  it  and  the  rectum,  into  the  urethra  ; and  there 
are  no  bags  similar  to  those  called  vesiculae  seminales  in  certain 
other  animals.* 

The  structure  of  the  penis  is  nearly  the  same  in  them  all,  and 
formed  much  upon  the  principle  of  the  quadruped.  It  is  made  up 
of  two  crura,  uniting  into  one  corpus  cavernosum,  and  the  corpus 
spongiosum  seems  first  to  enter  the  corpus  cavernosum.  In  the 
porpoise,  at  least,  the  urethra  is  found  nearly  in  the  centre  of  the 
corpus  cavernosum  ; but  towards  the  glans  seems  to  separate  or 
emerge  from  it,  and  becoming  a distinct  spongy  body,  runs  along 
its  under  surface,  as  in  quadrupeds.  The  corpus  cavernosum  in 
some  is  broader  from  the  upper  part  to  the  lower  than  from  side  to 
side;  but  in  the  porpoise  has  the  appearance  of  being  round, 
becoming  smaller  forwards,  so  as  to  terminate  almost  in  a point 
some  distance  from  the  end  of  the  penis.f  The  glans  does  not 
spread  out  as  in  many  quadrupeds,  but  seems  to  be  merely  a 
plexus  of  veins  covering  the  anterior  end  of  the  penis,  yet  is  ex- 
tended a good  way  further  on,  and  is  in  some  no  more  than  one 
vein  deep. 

The  crura  penis  are  attached  to  two  bones,  which  are  nearly  in 
the  same  situation  and  in  the  same  part  of  the  pelvis  as  those  to 
which  the  penis  is  attached  in  quadrupeds  ; but  these  bones  are  only 
for  the  insertion  of  the  crura,  and  not  for  the  support  of  any  other 
part,  like  the  pelvis  in  those  animals  which  have  posterior  extremi- 
ties, neither  do  they  meet  at  the  fore  part,  or  join  the  vertebras  of 
the  back.J  - 

the  abdominal  cavity  ; they  measured  each  nine  inches  in  length  and  four  inches 
in  the  shortest  diameter,  and  weighed  together  four  pounds  avoirdupois.  The 
corpus  Highmorianum  occupied  the  middle  or  axis  of  the  gland,  as  in  all  testes 
which  are  subject  to  considerable  enlargement  at  the  period  of  the  rut ; and  the 
membranous  septa  radiate  from  this  body  to  the  tunica  albuginea.] 

* [The  epididymis  in  the  porpoise  is  of  an  elongated  triedral  form ; the  broadest 
facet  is  connected  by  a duplicature  of  peritonaeum  to  the  testes;  the  connexion  is 
close,  except  at  the  lower  part  of  the  gland,  where  the  membrane  is  half  an  inch 
broad.  The  vas  deferens  continues  to  be  convoluted,  as  in  other  testiconda,  to 
within  two  inches  of  its  termination  in  the  dilated  bulbous  part  of  the  urethra  : the 
lining  membrane  of  tlie  terminal  two  inches  of  the  vas  deferens  is  denser,  and  of 
a Jess  glandular  structure  than  the  preceding  part.] 

t [The  corpus  cavernosum  is  remarkable  for  the  thickness  of  its  fibrous  sheath, 
which  equals  that  of  the  contained  erectile  tissue ; the  fibres  composing  the  sheath 
affect  distinctly  two  directions,  the  external  ones  running  longitudinally,  the  in- 
ternal circularly.] 

J [These  bones  are  of  an  elongated  form,  and  are  regarded  by  Cuvier  as  analo- 
gous to  the  iliac  bones ; but  as  they  give  attachment  to  the  crura  penis,  and  as 
the  erectores  penis  arise  from  their  whole  outer  and  posterior  surfaces,  they  would 
seem  to  be  rather  the  homologues  of  the  ischia.  A strong  tendon  is  continued, 
in  the  porpoise,  from  the  anterior  and  internal  extremity  of  each  bone,  descends 
obliquely  inwards,  and  after  the  course  of  an  inch  and  a half  expands  into  a mus- 
cular belly,  which  joins  its  fellow  in  the  mesial  line  behind  the  rectum.  Below 
this  fleshy  belly  on  each  side  there  is  an  oval,  flattened,  slightly  concave  bone. 
The  comtnencement  of  the  urethra  is  surrounded  by  thick  capsule  of  muscular 
fibres,  which  arise  from  the  inner  and  anterior  part  of  the  ischia,  and  from  the 


3S8 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


The  erectores  penis  are  very  strong  muscles,  having  an  origin 
and  insertion  similar  to  those  of  the  human  subject. 

The  acceleratores  muscles  are  likewise  very  strong ; and  there 
is  a strong  and  long  muscle,  arising  from  the  anus,  and  passing  for- 
wards to  the  bulb  of  the  penis,  that  runs  along  the  under  surface  of 
the  urethra,  and  is  at  last  lost  or  inserted  in  the  corpus  spongiosum. 
This  muscle  draws  the  penis  into  the  prepuce,  and  throws  that  part 
of  the  penis  that  is  behind  its  insertion  into  a serpentine  form.  It  is 
common  to  most  animals  that  draw  back  the  penis  into  what  is 
called  the  sheath,  and  may  be  called  the  retractor  penis. 

In  all  the  females  which  I have  examined,  the  parts  of  genera- 
tion are  very  uniformly  the  same,  consisting  of  the  external  open- 
ing, the  vagina,  the  uterus,  fallopian  tubes,  fimbriaj,  and  ovaria. 

The  external  opening  is  a longitudinal  slit,  or  oblong  opening, 
whose  edges  meet  in  two  opposite  points,  and  the  sides  are  rounded 
oft’,  so  as  to  form  a kind  of  sulcus.  The  skin  and  parts  on  each 
side  of  this  sulcus  are  of  a looser  texture  than  on  the  common  sur- 
face of  the  animal,  not  being  loaded  with  oil,  and  allowing  of  such 
motion  of  one  part  on  another,  as  admits  of  dilatation  and  contrac- 
tion. The  vagina  passes  upwards  and  backwards  towards  the 
loins,  so  that  its  direction  is  diagonal  respecting  the  cavity  of  the 
abdomen,  and  then  divides  into  the  two  horns,  one  on  each  side  of 
the  loins  ; these  afterwards  terminating  in  the  fallopian  tubes,  to 
which  the  ovaria  are  attached.  From  each  ovarium  there  is  a 
small  fold  of  the  peritonaeum,  which  passes  up  towards  the  kidney 
of  the  same  side,  as  in  most  quadrupeds. 

The  inside  of  the  vagina  is  smooth  for  about  one-half  of  its  length, 
and  then  begins  to  form  something  similar  to  valves  projecting  to- 
wards the  mouth  of  the  vagina,  each  like  an  os  tinc^ ; these  are 
about  six,  seven,  eight,  or  nine  in  number.  Where  they  begin  to 
form,  they  hardly  go  quite  round,  but  the  last  arc  complete  circles. 
At  this  part  too  the  vagina  becomes  smaller,  and  gradually  de- 
creases in  width  to  its  termination.* 

From  the  last  projecting  part,  the  passage  is  continued  up  to  the 
opening  of  the  two  horns,  and  the  inner  surface  of  this  last  part  is 
thrown  into  longitudinal  rugre,  which  are  continued  into  the  horns. 
Whether  this  last  part  is  to  be  reckoned  common  uterus  or  vagina, 
and  that  the  last  valvular  part  is  to  be  considered  as  os  tineas,  I do 
not  know  ; but  from  its  having  the  longitudinal  rugas,  I am  inclined 
to  think  it  is  uterus,  this  structure  appearing  to  be  intended  for  dis- 
tinction.! 

inner  surface  of  the  oval  bones  above  mentioned.  These  fibres  seem,  therefore, 
to  correspond  with  Wilson’s  muscle  combined  with  the  muscular  part  of  the 
urethra.  They  envelope  a glandular  substance  analogous  to  a prostate.] 

* [A  muscle  arises,  on  each  side,  from  the  whole  length  of  the  ischial  hone,  and 
passing  inwards  is  inserted  into  the  external  surface  of  the  vagina,  and  into  the 
crura  of  the  clitoris.  This  body  is  situated  like  a projecting  ridge,  without  any 
preputial  fold,  between  the  thin  labia;.  On  each  side  of  the  clitoris  within  the 
mouth  of  the  vagina,  are  the  orifices  of  sinuses,  analogous  to  the  canals  of  Malpighi 
in  Ruminantia.] 

t [From  the  os  tincie,  which  Hunter  calls  the  last  projecting  part  of  the  vagina. 


OBSERVATIONS  ON  THE  STRUCTURE,  ETC. 


389 


The  horns  are  an  equal  division  of  this  part ; they  make  a gentle 
turn  outwards,  and  are  of  considerable  length.  Their  inner  surface 
is  thrown  into  longitudinal  rugae,  without  any  small  protuberances 
for  the  cotyledons  to  form  upon,  as  in  those  of  ruminating  animals  ;* 
and  where  they  terminate,  the  fallopian  tubes  begin. 

In  the  bottle-nose  whale  (Hyperoodon),  where  the  fallopian  tubes 
opened  in  the  horns  of  the  uterus,  they  were  surrounded  by  pendu- 
lous bodies  hanging  loose  in  the  horns. 

The  fallopian  tubes,  at  their  termination  in  the  uterus,  are  re- 
markably small  for  some  inches,  and  then  begin  to  dilate  rather 
suddenly;  and  the  nearer  to  the  mouth  the  more  this  dilatation 
increases,  like  the  mouth  of  a French  horn,  the  termination  of 
which  is  five  or  six  inches  in  diameter.f  They  are  very  full  of 
longitudinal  rugse  through  their  whole  length. 

The  ovaria  are  oblong  bodies  about  five  inches  in  length,  one 
end  attached  to  the  mouth  of  the  fallopian  tube,  and  the  other  near 
to  the  horn  of  the  uterus.J  They  are  irregular  on  their  external 
surface,  resembling  a capsula  renalis  or  pancreas.  They  have  no 
capsula,  but  what  is  formed  by  the  long  fallopian  tube. 

How  the  male  and  female  copulate,  I do  not  know ; but  it  is 
alleged  that  their  position  in  the  water  is  erect  at  that  time,  which 
I can  readily  suppose  may  be  true  ; for  otherwise,  if  the  connection 
is  long,  it  would  interfere  with  the  act  of  respiration,  as  in  any 
other  position  the  upper  surface  of  the  heads  of  both  could  not  be  at 
the  surface  of  the  water  at  the  same  time.  However,  as  in  the 
parts  of  generation  they  most  resemble  those  of  the  ruminating  kind, 
it  is  possible  they  may  likewise  resemble  them  in  the  duration  of  the 
act  of  copulation ; for,  1 believe,  all  the  ruminants  are  quick  in  this 
act. 

Of  their  uterine  gestation  I as  yet  know  nothing;  but  it  is  very 
probable  that  they  have  only  a single  young  one  at  a time,  there 
being  only  two  nipples.§  This  seemed  to  be  the  case  with  the  bot- 

to  the  beginning'  of  the  division  of  the  uterus,  in  the  porpoise,  is  about  two  inches. 
The  uterus  is  lined  with  a very  smooth  mucous  membrane;  a thin  layer  of  cel- 
lular substance  separates  this  from  the  muscular  tunic,  in  which  the  circular 
fibres  may  be  clearly  discerned.  The  external  tunic  is  derived  from  the  peri- 
toneum which  forms  the  broad  ligaments.] 

* [The  fcetus  has  neither  placenta  nor  colytodons,  but,  as  in  the  hog  and  camel, 
the  general  vascularity  of  the  chorion  is  subservient  to  its  nutrition  and  respiration. 
The  allantois  is  coextensive  in  its  development  with  the  chorion,  and  both  extend 
into  the  horns  of  the  uterus.] 

t [The  margin  of  this  opening,  in  the  porpoise,  is  entire,  without  fimbriated 
processes.] 

t [In  the  porpesse  the  ovaria  are  attached  to  the  ovarian  ligament,  and  are  situ- 
ated half  way  between  the  expanded  orifice  of  the  fallopian  tube  and  the  extremity 
of  the  uterine  horn.] 

§ [The  dolphin  has  generally  one,  but  sometimes  two  at  a birth,  according  to 
Aristotle.  According  to  Pallas,  the  Beluga  {Delphinvs  Leucas)  brings  forth  two, 
but  the  exception  to  the  general  rule  may  have  been  observed  in  this  case ; since 
Fabricius  describes  the  same  species  as  being  uniparous(Fauna  Grcenlandica,  p.  51). 
The  Greenland  whale  brings  forth  a single  young  one  in  April.  The  spermaceti 
whale  produces  one  voung  one  every  year,  accordino-  to  Mr.  Beale  (Obs.  on  the 

34* 


390 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


tle-nose  whale  caught  near  Berkeley,  which  had  been  seen  fpr 
some  days  with  one  young  one  following  it,  and  they  were  both 
caught  together. 

The  glands  for  the  secretion  of  milk  are  two,  one  on  each  side 
of  the  middle  line  of  the  belly  at  its  lower  part.  The  posterior 
ends,  from  which  go  out  the  nipples,  are  on  each  side  of  the  open- 
ing of  the  vagina,  in  small  sulci.  They  are  flat  bodies  lying 
between  the  external  layer  of  fat  and  abdominal  muscles,  and  are 
of  considerable  length,  but  only  one-fourth  of  that  in  breadth. 
They  are  thin,  that  they  may  not  vary  the  external  shape  of  the 
animal,  and  have  a principal  duct,  running  in  the  middle  through 
the  whole  length  of  the  gland,  and  collecting  the  smaller  lateral 
ducts,  which  are  made  up  of  those  still  smaller.  vSome  of  these 
lateral  branches  enter  the  common  trunk  in  the  direction  of  the 
milk’s  passage,  others  in  the  contrary  direction,  especially  those 
nearest  to  the  termination  of  the  trunk  in  the  nipple.  The  trunk  is 
large,  and  appears  to  serve  as  a reservoir  for  the  milk,*  and  ter- 
minates externally  in  a projection,  which  is  the  nipple.  The  lateral 
portions  of  the  sulcus  which  incloses  the  nipple  are  composed  of 
parts  looser  in  texture  than  the  common  adipose  membrane,  which 
is  probably  to  admit  of  the  elongation  or  projection  of  the  nipple. 
On  the  outside  of  this  there  is  another  small  fissure,  which,  I ima- 
gine, is  likewise  intended  to  give  greater  facility  to  the  movements 
of  all  these  parts. 

The  milk  is  probably  very  rich  ; for  in  that  caught  near  Berke- 
ley with  its  young  one,  the  milk  which  was  tasted  by  Mr.  Jenner 
and  Mr.  Ludlow,  surgeon,  at  Sodbury,  was  rich,  like  cow’s  milk 
to  which  cream  had  been  added. 

The  mode  in  which  these  animals  must  suck  would  appear  to  be 
very  inconvenient  for  respiration,  as  either  the  mother  or  young 
one  will  be  prevented  from  breathing  at  the  time,  their  nostrils 
being  in  opposite  directions;  therefore  the  nose  of  one  must  be 
under  w'ater,  and  the  time  of  sucking  can  only  be  between  each 
respiration.  The  act  of  sucking  must  likewise  be  different  from 
that  of  land  animals;  as  in  them  it  is  performed  by  the  lungs 
drawing  the  air  from  the  mouth  backwards  into  themselves,  which 
the  fluid  follows,  by  being  forced  into  the  mouth  from  the  pressure 
of  the  external  air  on  its  surface;  but  in  this  tribe,  the  lungs  having 
no  connection  with  the  mouth,  sucking  must  be  performed  by 

Sperm.  Whale,  8vo.,  p.  36).  Mr.  F.  D.  Bennett  found  in  a gravid  cachalot 
a single  feetus  fourteen  feet  in  length,  and  si.x  in  girth ; its  position  in  the 
uterus  was  that  of  a bent  bow.  (Zool.  Proceed , Dec.  1836.)  When  brought 
forth  the  young  cachalot  is  usually  twenty  feet  in  lengtli.  And  we  may  observe 
that  the  cetacea  in  general  are  remarkable  for  the  large  size  of  the  foetus  at  birth. 
Camper  describes  the  new-born  porpoise  as  being  half  the  size  of  the  parent. 
(Ohs.  Anatomiques  sur  les  Cetaces,  p.  147.)  The  rudimental  condition  of  the 
pelvis  renders  the  birth  easy.] 

* [From  this  reservoir  the  milk  is  injected  into  the  mouth  of  the  young  by  the 
action  of  pow'erful  cutaneous  muscles,  arranged  bo  as  to  compress  the  reservoir  and 
dilated  ducts  of  the  mammary  glands.] 


ON  THE  ANATOMY  OF  THE  JERBOA. 


391 


some  action  of  the  mouth  itself,  and  by  its  having  the  power  of 
expansion.* 


NOTES  ON  THE  ANATOMY  OF  THE  JERBOA, 
{Dipus  Sagitta,  Gm.) 

(Extracted  from  the  Appendix  to  Russel’s  History  of  Aleppo,  where  they  are  thus 

introduced.) 

“ Having  met  with  nothing  more  on  the  internal  structure  of  the 
jerboa  than  what  is  given  by  Gmelin  from  M.  Buflbn  {Hist.  Nat. 
tom.  xiii.),  I applied  to  my  worthy  friend  Mr.  John  Hunter,  who 
very  obligingly  favoured  me  with  the  following  circumstances  from 
his  Adversaria  by  way  of  supplement.  He  was  not  certain  whether 
the  animal  he  dissected  was  from  Asia  or  Africa.” 

....The  meatus  auditorius  was  large  like  that  of  a bird.  The 
tympanum  was  also  large.f  There  are  two  venae  cavae  superiores. 
The  caecum  was  four  inches  in  length ; it  makes  a close  turn  upon 
itself,  and  gradually  diminishing  in  size,  terminates  in  an  obtuse 
point.  The  colon,  which  is  large  at  its  beginning,  passes  first  up- 
wards upon  the  right  side,  and  before  crossing  the  abdomen  on  the 
left,  makes  a little  fold  upon  itself;  it  then  crosses  the  spine,  and 
making  another  fold  shorter  than  the  former,  it  passes  the  left  side 
and  commences  rectum. 

The  lower  part  of  the  abdomen  lies  upon  the  anterior  part  of  the 
pubes,  and  the  bend  of  the  penis  is  seen  within  the  cavit)^  of  the 
abdomen,  making  a little  projection,  as  it  were,  between  the  origin 
of  the  two  musculi  recti.  The  penis  in  a flaccid  state  lies  reverted 
upon  itself,  but  when  in  erection  has  a bone  on  each  side  of  the 
part  projecting,  in  the  same  manner  as  in  the  guinea-pig.  The 
prepuce  is  furnished  with  a number  of  glands  which  secrete  a thick 
mucus.  The  testicles  are  situated  on  each  side  of  the  symphysis, 
and  can  occasionally  lie  in  the  rings  of  the  abdominal  muscles, 
which  are  very  large,  but  can  never  descend  much  further,  there 
being  no  scrotum  for  their  reception.  The  vesiculse  seminales  are 
two  long  bags,  which  make  a turn  upon  themselves.  The  anus 
is  bent  downwards  towards  the  parts  of  generation.^ 

* [Aided,  as  in  the  Marsupiata  and  Monotreinala,  by  muscular  actions  on  the 
part  of  tlie  parent  tending  to  expel  the  milk.] 
f [See  the  Preparation  No.  1599  Physiological  Series,  Hunter  Museum,  which 
is  most  probably  the  part  here  described,  and  if  so,  proves  the  description  to  be 
of  the  Bipus  Sagitta.] 

[These  short  and  simple  notes  are  interesting  as  an  example  of  the  matter 
composing  the  lost  '■^Adversaria ''  or  manuscript  notes  of  Hunter.  The  compari- 
son which  he  makes  with  reference  to  the  structure  of  the  ear-passage  shows  that 
lie  was  alive  to  those  interesting  points  of  structure  which  are  indicative  of  the 
natural  affinities  of  different  groups  of  animals.  The  jerboa  not  only  resembles 
the  bird  in  the  large  size  of  the  meatus  auditorius,  but  also  (together  with  the 


392 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


35.  ANATOMICAL  DESCRIPTION  OF  THE  AMPHIBIOUS 
BIPES  OF  ELLIS,  {Siren  Lacertina,  Linn.) 

BY  MR.  JOHN  HUNTER,  F.R.S.* 

The  tongue  is  broad  and  has  very  little  motion.  It  has  a bone 
similar  to  that  in  birds,  turtles,  &c.  On  the  posterior  and  lateral 


whole  order  of  Rodentia)  in  the  unanchylosed  state  of  the  tympanum  with  the 
other  elements  of  the  temporal  bone.  In  the  affinity  to  the  oviparous  vertebrata 
manifested  in  the  two  superior  cavae,  the  genus  Bipus  agrees  with  the  following 
rodent  genera  : Aladaga,  Hdamys,  Echimys,  Hystrix,  Sciurus,  Fteromys,  Oryc- 
teropus,  Bathyergus,  Lepus,  and  Ccelogenys,  I have  also  shown  that  the  same 
structure  characterizes  the  marsupial  animals.  See  Proceedings  of  the  Zoological 
Society,  April  1832.] 

* [This  paper  was  read  before  the  Royal  Society  June  5,  1760,  and  is  interest- 
ing from  the  circumstance  of  its  being  the  first  which  Hunter  communicated  to 
that  learned  body,  as  well  as  from  its  being  the  earliest  contribution  to  the  anato- 
my of  one  of  the  most  singular  tribes  of  animals  at  present  in  existence,  viz.  the 
Batrachia perennibranchiata , or  true  Amphibia.  The  sirens  dissected  by  Hunter 
were  brought  from  South  Carolina  in  1758,  and  purchased  along  with  other  sub- 
jects of  natural  history  by  Mr.  Hunter;  the  specimens  described  by  Ellis  were 
transmitted  to  him  by  Dr.  Alexander  Gardner,  of  Charles  Town,  South  Carolina. 
The  natives  call  the  siren  “mudiguana.”  It  is  found  in  swampy  and  muddy 
places  by  the  sides  of  pools,  under  the  trunks  of  old  trees  that  hang  over  the 
water.  The  external  description  of  the  siren  by  Mr.  Ellis  is  given  in  the  expla- 
nation of  the  plate  lii.,  p.  23. 

Besides  the  siren,  Mr.  Hunter  also  obtained  two  other  species  of  pererinibran- 
chiate  reptiles,  dissections  of  which  are  preserved  in  his  museum,  and  recorded 
in  his  manuscripts  under  the  names  of  “ Kallewagoef  (the  Menopoma  Alleghan- 
niensis  of  Dr.  Harlan)  and  the  “Amphibious  quadruped,”  since  particularly 
described  by  Cuvier  under  the  name  of  “ Amphiuma.”  The  types  of  three 
other  genera  of  perennibranchiata  have  subsequently  been  described,  and  the 
whole  tribe  is  divided  into  those  which  retain  the  external  branchiae  throughout 
life,  and  those  w'hich  lose  these  vascular  processes,  but  retain  the  gill  apertures. 

The  sirens  and  menobranchus  of  the  United  States,  the  axolotl  of  Mexico, 
and  the  proteus  of  Hungary  have  external  fimbriated  branchiae,  while  the  am- 
phiuma and  menopoma  have  only  the  branchial  arches  and  apertures,  but  not 
external  gills.  These  genera  are  all  perfectly  distinct  from  each  other  both  in  their 
external  and  anatomical  characters,  and  it  is  only  with  respect  to  one  of  them,  viz. 
the  axolotl,  that  any  doubt  still  remains  as  to  whether  the  gills  are  permanent  or 
not. 

At  the  period  of  the  discovery  of  the  siren  it  was  natural  to  suppose  from  the 
analogy  of  the  newt  and  salamander  that  it  was  a larva,  representing  an  immature 
stage  of  its  existence,  on  which  subject  Linn^us  thus  cautiously  expresses  him- 
self in  a letter  to  Mr.  Ellis. 

“ Upsal,  December  27,  1765.  I received  Dr.  Garden’s  very  rare  two-footed 
animal  with  gills  and  lungs.  The  animal  is  probably  the  larva  of  some  kind  of 
Lacerta,  which  1 very  much  desire  that  he  will  particularly  inquire  into. 

“ If  it  does  not  undergo  a change,  it  belongs  to  the  order  of  Nantes,  which 
have  both  lungs  and  gills  ; and  if  so,  it  must  be  a new  and  very  distinct  genus, 
and  should  most  probably  have  the  name  of  Siren. 

“I  cannot  possibly  describe  to  you  how  much  this  two-footed  animal  has  ex- 
ercised my  thoughts  ; if  it  is  a larva  he  will  no  doubt  find  some  of  them  with  four 
feet.  It  is  not  an  easy  matter  to  reconcile  it  to  the  larva  of  the  lizard  tribe,  its 


ANATOMICAL  DESCRIPTION,  ETC. 


393 


parts  of  the  mouth  are  three  openings  on  each  side ; these  are 
similar  to  the  slits  of  the  gills  in  fish,  but  the  partitions  do  not 
resemble  gills  on  their  outer  edges,  for  they  have  not  the  comb-like 
structure.  Above*  and  close  to  the  extremity  of  each  of  these 
openings  externally,  so  many  processes  arise,  the  anterior  the 
smallest,  the  posterior  the  largest;  their  anterior  and  inferior  edges 
and  extremity  are  serrated,  or  formed  into  fimbrias  ; these  pro- 
cesses fold  down  and  cover  the  slits  externally,  and  wmuld  seem  to 
answer  the  purposes  of  the  comb-like  part  of  the  gill  in  fish. 

At  the  root  of  the  tongue,  nearly  as  far  back  as  these  openings 
reach,  the  trachea  begins  much  in  the  same  manner  as  in  birds. 
It  passes  backwards  above  the  heart,  and  there  divides  into  two 
branches,  one  going  to  each  lobe  of  the  lungs.  The  lungs  are  two 
long  bags,  one  on  each  side,  which  begin  just  behind  the  heart,  and 
pass  back  through  the  wdiole  length  of  the  abdomen,  nearly  as  far 
as  the  anus.  They  are  largest  in  the  middle,  and  honey-combed 
on  the  internal  surface  through  their  whole  length.  The  heart 
consists  of  one  auricle  and  one  ventricle.  What  answers  to  the 
inferior  vena  cava  passes  forwards  above,  but  in  a sulcus  of  the 
liver,  and  opens  into  a bag  similar  to  the  pericardium;  this  bag 

fingers  being  furnished  with  claws  ; all  the  larvas  of  lizards  that  I know  are 
without  them  (“  digilis  muticis'”).  Then  also  the  branchiae  or  gills  are  not  to  be 
met  with  in  the  aquatic  salamanders,  which  are  probably  the  larvas  of  lizards. 
Further,  the  croaking  noise  or  sound  it  makes  does  not  agree  with  the  larvas  of 
these  animals,  nor  does  the  situation  of  the  anus.  So  that  there  is  no  creature 
that  ever  I saw  that  I long  so  much  to  be  convinced  of  the  truth  as  to  what  this 
will  certainly  turn  out  to  be.” 

Dr.  Pockells  of  Brunswick,  who  visited  the  Museum  of  the  Royal  College  of 
Surgeons,  in  1820,  perceiving  some  specimens  of  Amphiuma,  concluded  from 
their  having  four  legs  and  no  external  gills  that  they  were  the  adult  or  perfect 
Siren,  and  Rusconi  adopted  this  opinion  without  further  investigation  ; but 
Cuvier  has  shown  that  the  Amphiuma  differs  from  the  Siren  in  its  osteological 
structure,  having  in  one  species  ten,  and  in  another  twenty-two  additional  verte- 
brae, while  the  construction  of  the  cranium  and  other  parts  of  the  skeleton  are 
totally  different : moreover  the  completely  ossified  state  of  the  skeleton  of  the 
Siren,  without  the  slightest  vestige  of  posterior  extremities,  proves  it  to  be  neither 
the  larva  of  an  Amphiuma  or  of  any  other  known  Amphibian. 

See  Rusconi,  Anat.  ddle  larve  Salamandre,  ito,,  1817;  Del  Prof eo  An- 

guino,  4to.,  1819  ; and  Amours  des  Salamandres,  fol.  1826,  p.  12.  Cuvier, 
Reclierches  sur  les  Bepfiles  douieux,  in  Humboldt’s  Obs,  ZooL,  4to.,  1811-1827  ; 
Ossemens  Fossiles,  tom.  v.  pt.  2 : Mem.  du  Mas.,  tom.  xiv.  See  also  “ A Notice 
of  a Siren  Lacertina'''  kept  alive  at  Canon  Mills,  Edinburgh,  for  more  than  six 
years,  in  Jamieson’s  Journal,  1832,  p.  298.  From  the  observations  made  on 
this  animal  it  appears  that  the  branchis  are  the  respiratory  organs  most  essential 
to  its  existence,  and  its  death  is  supposed  to  have  been  occasioned  by  the  fim- 
briae of  the  gills  becoming  completely  dried  and  shrivelled  up,  in  consequence 
of  its  accidentally  falling  out  of  the  box  of  water  in  which  it  was  habitu- 
ally kept.  It  ate  worms,  sticklebacks,  and  small  minnows  greedily  ; and  showed 
great  alertness  and  sagacity  in  concealing  itself  most  accurately  beneath  a floating 
patch  of  frog-bit. 

* To  avoid  the  confusion  in  our  ideas  which  might  arise  from  the  use  of  the 
words  anterior,  posterior,  upper,  lower,  &c.,  in  the  whole  of  this  description  the 
animal  is  considered  in  its  natural  horizontal  position,  so  that  the  head  is  for- 
wards, the  back  upwards,  &e. 


394 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


surrounds  the  heart  and  aorta,  as  the  pericardium  does  in  other 
animals  ; from  this  there  is  an  opening  into  a vein  which  lies 
above,  and  upon  the  left  of  the  auricle,  which  vein  seems  to  receive 
the  blood  from  the  lungs,  gills,  and  head,  is  analogous  to  the  supe- 
rior vena  cava,  and  opens  into  the  auricle,  which  is  upon  the  left  of 
the  ventricle.  The  aorta  goes  out,  passing  for  a little  way  in  a 
loose  spiral  turn,  then  becomes  straight,  where  it  seems  to  be  mus- 
cular; at  this  part  the  branches  go  off,  between  which  there  is  a 
rising  within  the  area  of  the  aorta  like  a bird’s  tongue,  with  its  tip 
turned  towards  the  heart.*  The  liver  is  principally  one  lobe, 
pretty  close  to  the  heart  at  the  fore  part,  and  passes  back  on  the 
right  of  the  stomach  and  intestines;  at  its  anterior  extremity  on  the 
left  side  there  is  a very  short  lobe,  ending  abruptly.  The  gall- 
bladder lies  in  a fissure  on  the  left  side  of  the  liver  near  its  middle; 
there  is  no  hepatic  duct ; the  hepato-cystic  ducts,  which  seem  to  be 
three  in  number,  enter  the  gall-bladder  at  its  anterior  end  or  fundus, 
and  the  cystic  duct  passes  out  from  the  posterior  end  of  the  gall- 
bladder, and  terminates  in  the  gut,  about  half  an  inch  from  the 
pylorus.  The  oesophagus  which  is  pretty  large,  passes  back,  and 
is  continued  into  the  stomach  in  the  same  line.  The  stomach  at 
the  posterior  end  bends  a little  to  the  right,  w’here  it  terminates  in 
the  pylorus.  The  intestines  pass  back,  making  many  turns  ; at  the 
posterior  end  they  become  pretty  straight,  forming  what  may  be 
called  the  colon,  or  rectum,  W'here  they  are  a little  larger,  and  run 
to  the  anus  in  a straight  direction.  At  the  beginning  of  this  larger 
part  of  the  intestinal  tube  there  is  no  valvular  structure.  The  spleen 

* Tliis  account  of  the  vena3  cavce  opening  into  the  cavity  of  the  pericardium 
may  appear  incredible  ; and  it  might  be  supposed  that,  in  the  natural  state  of  the 
parts,  there  is  a canal  of  communication  going  from  one  cava  to  the  other,  which 
being  broken  or  nipped  through,  in  the  act  of  catching  or  killing  the  animal, 
would  give  the  appearance  above  described.  I can  only  say  that  the  appearances 
were  what  have  been  described  in  three  different  subjects  which  I have  dissected; 
and  in  all  of  them  the  pericardium  was  full  of  coagulated  blood.  But  besides  the 
smallness  of  the  subjects,  it  may  be  observed  that  they  had  been  long  preserved 
in  spirits,  which  made  them  more  unfit  for  anatomical  inquiries.  They  had  been 
in  my  possession  above  seven  years.* 


^ [There  is  no  preparation  in  the  Hunterian  Collection  demonstrative  of  the 
structure  described  in  the  text,  and  it  was  in  the  dissection  of  the  siren,  instituted 
with  the  view  to  reconcile  or  account  for  Hunter’s  description  of  the  heart,  that 
1 was  led  to  the  discovery  of  the  two  distinct  auricles  in  that  animal.  {Tram. 
Zool.  Soc.,  vol.  i.,  p.  213,  April,  1831.)  The  inferior  vena  cava  terminates  at  the 
lower  part  of  a large  membranous  sinus,  which  also  receives  the  blood  from  the 
two  superior  cavas  by  two  separate  orifices.  The  common  trunk  of  the  pulmonary 
veins  seems  also  to  end  in  this  sinus,  but  it  merely  traverses  without  communi- 
cating with  it,  and  finally  opens  into  a distinct  transverse  auricular  chamber, 
which  is  not  sejiarated  externally  from  the  apparently  single  and  capacious  auri- 
cle of  the  venae  cavs,  which  is  characterized  by  numerous  elongated  fimbriated 
processes.  The  glistening  fibrous  coat  of  the  pericardium  closely  adheres  to  the 
surrounding  muscles  as  in  fish,  so  that  the  absence  of  any  detached  bag  sur- 
rounding the  heart,  the  magnitude  of  the  auricle,  and  the  peculiar  passage  of  the 
pulmonary  veins  through  the  great  sinus  of  the  venae  cavae  may  have  contributed 
to  mislead  Mr.  Hunter  as  to  the  real  structure  of  the  part.] 


OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO. 


395 


is  a very  small  but  long  body;  its  anterior  end  is  attached  to  the 
upper  surface  of  the  stomach,  and  it  is  continued  back  along  the 
left  side  of  the  mesentery,  to  which  it  adheres.  The  pancreas  is  a 
small  body  lying  above  the  duodenum,  and  is  attached  also  to  the 
mesentery.  The  kidneys  are  situated  in  the  upper  and  posterior 
part  of  the  abdomen,  having  the  rectum  passing  below  and  between 
them,  as  in  the  snake,  &c.  Below  the  rectum  lies  a long  bag,  like 
a bladder;  it  adheres  all  along  to  the  inside  of  the  abdominal  mus- 
cles, and  its  mouth  opens  into  the  rectum  ; but  whether  it  is  the 
bladder  of  urine  or  not  I cannot  tell.  On  each  side  of  the  rectum, 
close  to  the  lungs,  there  is  a body,  the  posterior  end  of  which  rests 
upon  the  anterior  end  of  the  kidney  ; whether  they  are  testicles  or 
ovaria  I cannot  pretend  to  determine,  but  should  imagine  that  they 
are  either  the  one  or  the  other.* 


36.  OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO. 

In  a Letter  from  John  Walsh,  Esq.,  F.R.S.,  to  Benjamin  Franklin,  Esq.,  L.L.D* 
F.R.S.,  Ac.  R.  Par.  Soc.  Ext.,  (fec.-j" 


Chesterfield  Street,  July  1,  1"73. 

Dear  Sir, 

I AM  concerned  that  other  engagements  have  prevented  me 
from  giving  to  the  Royal  Society,  before  their  recess,  a complete 
account  of  my  experiments  on  the  electricity  of  the  torpedo;  a 
subject  not  only  curious  in  itself,  but  opening  a large  field  for  in- 
teresting inquiry,  both  to  the  electrician  in  his  walk  of  physics, 
and  to  all  who  consider,  particularly  or  generally,  the  animal 
CEConomy. 

To  supply  the  deficiency  in  the  best  manner  I am  now  able,  I 
will  request  the  favour  of  you  to  lay  before  the  Society  my  letter 


* [The  ovaria  in  the  siren  are  irregularly  shaped  elongated  somewhat  com- 
pressed bodies,  becoming  smaller  at  the  two  extremities.  In  a siren  of  two  feet 
long  they  were  each  four  inches  in  length,  and  half  an  inch  broad,  both  situated 
at  the  lower  and  back  part  of  the  abdomen : the  left  about  an  inch  nearer  the 
head,  having  a smooth  surface  outwardly,  and  moulded  on  the  inner  surface  to  the 
convolutions  of  the  intestine.  The  stroma  ovarii  was  crowded  with  very  numerous 
and  minute  ovisacs  of  a whitish  colour,  and  was  studded  here  and  there  with 
larger  drops  of  a dark-coloured  oil.  The  oviducts  extend  from  the  cloaca,  in  the 
form  of  broad,  flattened,  membranous  canals,  to  near  the  anterior  ends  of  the  ovaria, 
where  they  alter  their  form  and  become  rounded  tubes,  each  becoming  folded  upon 
itself  in  broad  close-set  plaits,  and  terminating,  without  change  of  dimensions,  in 
a longitudinal  slit,  which  occupies  part  of  the  anterior  surface  of  the  last  plait. 
The  oviducts  are  attached  by  a broad  fold  of  peritoneum  to  the  dorsal  region  of 
the  abdomen.] 

t [This  letter  is  prefixed  to  Mr.  Hunter’s  description  of  the  Electric  Organs,  in 
the  Philosophical  Transactions,  vol.  Ixiii.] 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


39  G 

from  La  Rochelle,  of  the  12th  July,  1772,  and  such  part  of  the  let- 
ter I afterwards  wrote  from  Paris  as  relates  to  this  subject.  Loose 
and  imperfect  as  these  informations  are,  for  they  were  never  in- 
tended for  the  public  eye,  they  are  still  the  most  authentic,  and  so 
far  the  most  satisfactory  I can  at  present  offer,  since  the  notes  I 
made  of  the  experiments  themselves  remain  nearly,  I am  sorry  to 
say  it,  in  that  crude  and  bulky  state  in  which  you  had  the  trouble 
to  read  them. 

Letter  fro?n  Mr.  Walsh  to  Dr.  Franklin,  dated  La  Rochelle,  July  12, 

1772. 

“ It  is  with  particular  satisfaction  I make  to  you  my  first  com- 
munication, that  the  efiect  of  the  torpedo  appears  to  be  absolutely 
electrical;  by  forming  its  circuit  through  the  same  conductors  with 
electricity,  for  instance,  metals  and  water  ; and  by  being  inter- 
cepted by  the  same  non-conductors,  for  instance,  glass  and  sealing- 
wax.  I will  not  at  present  trouble  you  with  the  detail  of  our  expe- 
riments, especially  as  we  are  daily  advancing  in  them,  but  only 
observe  that  we  have  discovered  the  back  and  breast  of  the  animal 
to  be  in  different  states  of  electricity  ; I mean  in  particular  the  upper 
and  lower  surfaces  of  those  two  assemblages  of  pliant  cylinders  of 
which  you  have  seen  engravings  in  Lorenzini.*  By  the  knowledge 
of  this  circumstance  we  have  been  able  to  direct  his  shocks,  though 
they  were  very  small,  through  a circuit  of  four  persons,  all  feeling 
them  ; likewise  through  a considerable  length  of  wire  held  by  two 
insulated  persons,  one  touching  his  lower  surface,  and  the  other  his 
upper.  When  the  wire  was  exchanged  for  glass  or  sealing  wax  no 
effect  could  be  obtained,  but  as  soon  as  it  was  resumed  the  two 
persons  became  liable  to  the  shock.  These  experiments  have  been 
varied  many  ways  and  repeated  times  without  number,  and  they 
all  determined  the  choice  of  conductors  to  be  the  same  in  the  torpedo 
as  in  the  Leyden  phial.  The  sensations  likewise  occasioned  by  one 
and  the  other  in  tlie  human  frame  are  precisely  similar.  Not  only 
the  shock,  but  the  numbing  sensation  which  the  animal  sometimes 
dispenses,  expressed  in  French  by  the  words  engourdissement  and 
fourmillement,  may  be  exactly  imitated  with  the  phial,  by  means  of 
Lane’s  electrometer,  the  regulating  rod  of  which,  to  produce  the 
latter  effect,  must  be  brought  almost  into  contact  with  the  prime 
conductor  which  joins  the  phial.  We  have  not  yet  perceived  any 
spark  to  accon)pany  the  shock,  nor  the  pith  balls  to  be  ever  affected. f 

* Observazioni  intorno  alle  Torpedini  di  Stef  Lorenzini,  1678. 

Redi  appears  to  be  the  first  who  remarked  these  singular  parts  of  the  torpedo 
in  1666.  Franc.  Redi,  Exper.  Nat. 

f [Gardini  and  Galvani,  and  more  recently  Matteuci,  concur  in  stating  that 
they  have  seen  a feeble  spark  from  the  discharge  of  a torpedo,  but  other  philoso- 
phers have  not  been  so  successful.  The  observations  of  Dr.  John  Davy  on  this 
point  (Philos.  Trans.,  18.‘14)  particularly  deserve  attention.  He  experimented 
on  very  active  fish,  and  varied  his  trials,  with  every  endeavour  to  obtain  the  re- 


OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO. 


397 


Indeed,  all  our  trials  have  been  done  on  very  feeble  subjects,  whose 
shock  was  seldom  sensible  beyond  the  touching  finger.  I remember 
but  one,  of  at  least  two  hundred  that  I myself  must  have  received, 
to  have  extended  above  the  elbow.  Perhaps  the  Isle  of  Re,  which 
we  are  about  to  visit,  may  furnish  us  wdth  torpedos  fresher  taken 
and  of  more  vigour,  by  which  a further  insight  into  these  matters 
may  be  had.  Our  experiments  have  been  chiefly  in  the  air,  where 
the  animal  was  more  open  to  our  examination  than  in  water.  It  is 
a singularity  that  the  torpedo,  when  insulated,  should  be  able  to 
give  to  us,  insulated  likewise,  forty  or  fifty  successive  shocks  from 
nearly  the  same  part,  and  these  with  little,  if  any,  diminution  in 
their  force ; indeed,  they  were  all  very  minute.  Each  effort  in  the 
animal  to  give  the  shock  is  conveniently  accompanied  with  a depres- 
sion of  his  eyes,  by  which  even  his  attempts  to  give  it  to  non-con- 
ductors can  be  observed.  The  animal,  wdth  respect  to  the  rest  of 
his  body,  is  in  a great  degree  motionless,  but  not  wholly  so.  You 
will  please  to  acquaint  Dr.  Bancroft  of  our  having  thus  verified  his 
suspicion  concerning  the  torpedo,*  and  make  any  other  communi- 
cation of  this  matter  you  may  judge  proper.  Here  I shall  be  glad 
to  excite,  as  far  as  I am  able,  both  electricians  and  naturalists  to 
push  their  inquiries  concerning  this  extraordinary  animal,  whilst 
the  summer  affords  them  the  opportunity.” 


Extracts  of  a Letter  from  Mr.  Walsh  to  Dr.  Franklin,  dated  Paris 
.dugust  27,  1772. 

“ I spent  a complete  week  in  my  experiments  at  the  Isle 

of  Re,  and  had  there  every  convenience  for  prosecuting  them  to  their 
extent,  except  that  I was  restrained  by  the  jealousy  of  the  govern- 
ment from  making  them  where  the  animal  was  caught.  At  my 
return  to  La  Rochelle,  I communicated  to  the  members  of  the 
Academy  of  that  place  and  to  many  of  the  principal  inhabitants  all 
that  I had  observed  concerning  the  torpedo,  in  the  intention  of 

quired  result,  but  never  procured  a spark.  By  means  of  Harris’s  electrometer, 
however,  he  saw  proof  of  the  evolution  of  heat  during  the  torpedo’s  discharge. 
Abundant  evidence  of  the  chemical  effects  of  animal  electricity  has  been  obtained 
by  tlie  same  philosopher.  He  applied  golden  wires,  one  to  the  dorsal,  the  other 
to  the  ventral  surface  of  the  torpedo,  and  passed  the  discharge  through  solutions 
of  nitrate  of  silver,  common  salt,  and  superacetate  of  lead,  and  found  that  all 
were  decomposed,  but  the  latter  substance  only  when  the  fish  seemed  to  put  forth 
all  its  energy,  after  being  much  irritated  (Philos.  Trans.,  1832).  In  resuming 
the  inquiry  instituted  by  Sir  Humphry  Davy,  relative  to  the  magnetical  effects 
of  the  torpedo's  discharge,  Dr.  .John  Davy  ascertains  in  the  most  satisfactory 
manner  that  these  effects  were  produced  by  animal  electricity.  He  placed  eight 
needles  within  a spiral  of  fine  copper  wire,  containing  about  one  hundred  and 
eighty  convolutions,  and  having  passed  through  this  a single  discharge  from  a 
torpedo  six  inches  long,  the  contained  needles  were  all  converted  into  magnets,  and 
the  ends  of  the  needles  which  were  nearest  the  ventral  surface  of  the  fish  had 
received  the  southern  polarity.  See  Phil.  Trans.,  1829.] 

* Bancroft’s  Natural  History  of  Guiana,  p.  194. 

35 


398 


HUNTER  ON  THE  ANIMAL  CECONOMY, 


Stirring  up  a spirit  of  inquiry  both  as  to  its  electricity  and  general 
osconomy. 

“ The  vigour  of  the  fresh-taken  torpedos  at  the  Isle  of 

Re  was  not  able  to  force  the  torpedinal  fluid  across  the  minutest 
tract  of  air ; not  from  one  link  of  a small  chain,  suspended  freely 
to  another ; not  through  an  almost  invisible  separation,  made  by  the 
edge  of  a penknife,  in  a slip  of  tinfoil  pasted  on  sealing-wax.  The 
spark,  therefore  (of  course  the  attendant  snapping  noise),  was 
denied  to  all  our  attempts  to  discover  it,  not  only  in  daylight,  but 
in  complete  darkness.  I observed  to  you  in  my  last  the  singularity 
of  the  torpedo  being  able,  when  insulated,  to  give  to  an  insulated 
person  a great  number  of  successive  shocks : in  this  situation  I have 
taken  no  less  than  fifty  from  him  in  the  space  of  a minute  and  a 
half.  All  our  experiments  confirmed  that  his  electricity  was  con- 
densed in  the  instant  of  its  explosion  by  a sudden  energy  of  the 
animal,  and  as  there  was  no  gradual  accumulation  nor  retention  of 
it,  as  in  the  case  of  charged  glass,  it  is  not  at  all  surprising  that  no 
signs  of  attraction  nor  repulsion  were  perceived  in  the  pith  balls. 
In  short,  the  effect  of  the  torpedo  appears  to  arise  from  a com- 
pressed elastic  fluid,  restoring  itself  to  its  equilibrium  in  the  same 
way  and  by  the  same  mediums  as  the  elastic  fluid  compressed  in 
charged  glass.  The  skin  of  the  animal,  bad  conductor  as  it  is, 
seems  to  be  a better  conductor  of  his  electricity  than  the  thinnest 
plate  of  elastic  air.  Notwithstanding  the  weak  spring  of  the  torpe- 
dinal electricity,  I was  able,  in  the  public  exhibitions  of  my  experi- 
ments at  La  Rochelle,  to  convey  it  through  a circuit,  formed  from 
one  surface  of  the  animal  to  the  other,  by  two  long  brass  wires 
and  four  persons,  which  number  at  times  was  increased  even  to 
eight.  The  several  persons  were  made  to  communicate  with  each 
other,  and  the  two  outermost  with  the  wires,  by  means  of  water 
contained  in  basins,  properly  disposed  between  them  for  the  pur- 
pose, each  person  dipping  his  hands  in  the  nearest  basins,  con- 
nectively  with  his  neighbour  on  either  side 

“ The  effect  produced  by  the  torpedo  when  in  air  appeared,  on 
many  repeated  experiments,  to  be  about  four  times  as  strong  as  when 
in  water.  ” 

A clear  and  succinct  narrative  of  what  passed  at  one  of  the  pub- 
lic exhibitions  alluded  to  in  the  last  letter  appeared  in  the  French 
Gazette  of  the  30th  October,  1772.  As  it  came  from  a very  re- 
spectable quarter,  not  less  so  from  the  private  character  of  the  gen* 
tleman  than  from  the  public  offices  he  held,  I must  desire  leave  of 
the  Society  to  avail  himself  of  such  a testimony  to  the  facts  I have 
advanced  by  giving  a translation  of  that  narrative. 


Extract  of  a Letter  from  the  Sieur  Seignette,  Mayor  of  La  Rochelle, 
and  Second  Perpetual  Secretary  of  the  Academy  of  that  City,  to 
the  publisher  of  the  French  Gazette, 

“ In  the  Gazette  of  the  14th  August,  you  mentioned  the  discovery 
made  by  Mr.  Walsh,  member  of  the  parliament  of  England,  and  of 


OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO.  399 


the  Royal  Society  of  London.  The  experiment  of  which  I am 
going  to  give  you  an  account,  was  made  in  the  presence  of  the 
Academy  of  this  city.  A live  torpedo  was  placed  on  a table. 
Round  another  table  stood  five  persons  insulated.  Two  brass 
wires,  each  thirteen  feet  long,  w'ere  suspended  to  the  ceiling  by  silken 
strings.  One  of  these  wires  rested  by  one  end  on  the  wet  napkin 
on  which  the  fish  lay ; the  other  end  was  immersed  in  a basin  full 
of  water  placed  on  the  second  table,  on  which  stood  four  others 
basins  likewise  full  of  water.  The  first  person  put  a finger  of  one 
hand  in  the  basin  in  which  the  wire  was  immersed,  and  a finger  of 
the  other  hand  in  the  second  basin.  The  second  person  put  a finger 
of  one  hand  in  this  last  basin,  and  a finger  of  the  other  hand  in  the 
third  ; and  so  on  successively,  till  the  five  persons  communicated 
with  one  another  by  the  water  in  the  basins.  In  the  last  basin  one 
end  of  the  second  wire  was  immersed  ; and  with  the  other  end  Mr. 
Walsh  touched  the  back  of  the  torpedo,  when  the  five  persons  felt 
a commotion  which  differed  in  nothing  from  that  of  the  Leyden 
experiment,  except  in  the  degree  of  force.  Mr.  Walsh,  who  was 
not  in  the  circle  of  conduction,  received  no  shock.  This  experi- 
ment was  repeated  several  times,  even  with  eight  persons,  and 
always  with  the  same  success.  The  action  of  the  torpedo  is  com- 
municated by  the  same  mediums  as  that  of  the  electric  fluid.  The 
bodies  which  intercept  the  action  of  the  one,  intercept  likewise  the 
action  of  the  other.  The  efiect  produced  by  the  torpedo  resemble 
in  every  respect  a weak  electricity.  ” 

This  exhibition  of  the  electric  powers  of  the  torpedo  before  the 
Academy  of  La  Rochelle,  was  at  a meeting  held  for  the  purpose 
in  my  apartments,  on  the  22d  July,  1772,  and  stands  registered  in 
the  journals  of  the  Academy. 

The  effect  of  the  animal  was,  in  these  experiments,  transmitted 
through  as  great  an  extent  and  variety  of  conductors  as  almost  at 
any  time  we  had  been  able  to  obtain  it,  and  the  experiments  in- 
cluded nearly  all  the  points  in  which  its  analogy  with  the  effect  of 
the  Leyden  phial  had  been  observed.  These  points  were  stated  to 
the  gentlemen  present,  as  were  the  circumstances  in  which  the  two 
effects  appeared  to  vary.  It  was  likewise  represented  to  them, 
that  our  experiments  had  been  almost  wholly  with  the  animal  in 
the  air;  that  its  action  in  water  was  a capital  desideratum;  that 
indeed  all  as  yet  done  was  little  more  than  opening  the  door  to  in- 
quiry ; that  much  remained  to  be  examined  by  the  electrician  as 
well  as  by  the  anatomist ; that  as  artificial  electricity  had  thrown 
light  on  the  natural  operation  of  the  torpedo,  this  might  in  return, 
if  well  considered,  throw  light  on  artificial  electricity,  particularly 
in  those  respects  in  which  they  now  seemed  to  differ  ; that  for  me, 
I was  about  to  take  leave  of  the  animal,  as  nature  had  denied  it  to 
the  British  seas  ; and  that  the  prosecution  of  these  researches  rested 
in  a particular  manner  with  them,  whose  shores  abounded  with  it. 

The  torpedo  on  this  occasion  dispensed  only  the  distinct,  instan- 
taneous stroke  so  well  known  by  the  name  of  the  electric  shock. 


400 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


That  protracted  but  ligliter  sensation,  that  torpor  or  numbness 
which  he  at  times  induces,  and  from  which  he  takes  his  name,  was 
not  then  experienced  from  the  animal;  but  it  was  imitated  with 
artificial  electricity,  and  shown  to  be  producible  by  a quick  conse- 
cution of  minute  shocks.  This  in  the  torpedo  may  perhaps  be  effect- 
ed by  the  successive  discharge  of  his  numerous  cylinders,  in  the 
nature  of  a running  fire  of  musketry  : the  strong  single  shock  may 
be  his  general  volley.  In  the  continued  effect,  as  well  as  in  the 
instantaneous,  his  eyes,  usually  prominent,  are  withdrawn  into  their 
sockets. 

The  same  experiments,  performed  wdth  the  same  torpedos,  were 
on  the  two  succeeding  days  repeated  befoi-e  numerous  companies 
of  the  principal  inhabitants  of  La  Rochelle.  Besides  the  pleasure 
of  gratifying  the  curiosity  of  such  as  entertained  any  on  the  sub- 
ject, and  the  desire  I had  to  excite  a prosecution  of  the  inquiry, 
I certainly  wished  to  give  all  possible  notoriety  to  facts,  which 
might  otherwise  be  deemed  improbable,  perhaps  by  some  of  the 
first  rank  in  science.  Great  authorities  had  given  a sanction  to 
other  solutions  of  the  phaenomena  of  the  torpedo;  and  even  the 
electrician  might  not  readily  listen  to  assertions,  wdiich  seemed  in 
some  respects  to  combat  the  general  principles  of  electricity.  I 
had  reason  to  make  such  conclusions  from  different  conversations  I 
had  held  on  the  subject  with  eminent  persons  both  at  London  and 
Paris.  It  is  but  justice  to  say,  that  of  all  in  that  class  you  gave  me 
the  greatest  encouragement  to  look  for  success  in  this  research, 
and  even  assisted  me  in  forming  hypotheses,  how  the  torpedo,  sup- 
posed to  be  endued  with  electric  properties,  might  use  them  in  so 
conducting  an  element  as  water. 

After  generally  recommending  to  others  an  examination  of  the 
electric  powers  of  these  animals  when  acting  in  water,  I determined, 
before  I took  my  final  leave  of  them,  to  make  some  further  experi- 
ments myself  with  that  particular  view;  since,  notwithstanding  the 
familiarity  in  which  we  may  be  said  to  have  live  with  them  for  near 
a month,  W'e  had  never  detected  them  in  the  immediate  exercise  of 
their  electric  faculties  against  other  fish,  confined  with  them  in  the 
same  water,  either  in  the  circumstance  of  attacking  their  prey,  or 
defending  themselves  from  annoyance  ; and  yet  that  they  possessed 
such  a power,  and  exercised  it  in  a state  of  liberty,  could  not  be 
doubted. 

A large  torpedo,  very  liberal  of  his  shocks,  being  held  with  both 
hands  by  his  electric  organs  above  and  below,  was  briskly  plunged 
into  water  to  the  depth  of  a foot,  and  instantly  raised  an  equal 
height  into  air  ; and  was  thus  continually  plunged  and  raised,  as 
quick  as  possible,  for  the  space  of  a minute.  In  the  instant  his 
lower  surface  touched  the  water  in  his  descent,  he  always  gave  a 
violent  shock,  and  another  still  more  violent  in  the  instant  of  quitting 
the  water  in  his  ascent ; both  which  shocks,  but  particularly  the  last, 
were  accompanied  with  a writhing  in  his  body,  as  if  meant  to  force 
an  escape  : besides  these  two  shocks  from  the  surface  of  the  water, 


OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO.  401 


which  may  yet  be  considered  as  delivered  in  the  air,  he  constantly 
gave  at  least  two  when  wholly  in  the  air,  and  constantly  one,  and 
sometimes  two,  when  wholly  in  the  water.  The  shocks  in  the 
water  appeared,  as  far  as  sensation  could  decide,  not  to  have  near  a 
fourth  of  the  force  of  those  at  the  surface  of  the  water,  nor  much 
more  than  a fourth  of  those  entirely  in  the  air. 

The  shocks  received  in  a certain  time  w’ere  not  on  this  occasion 
counted  by  a watch,  as  they  had  been  on  a former,  when  fifty  were 
delivered  in  a minute  and  a half  by  the  animal  in  an  insulated  and 
unagitated  state  : but  from  the  quickness  with  which  the  immersions 
were  made,  it  may  be  presumed  there  were  full  twenty  of  these 
in  a minute ; from  whence  the  number  of  shocks  in  that  time  must 
have  amounted  to  above  a hundred.  This  experiment,  therefore, 
while  it  discovered  the  comparative  force  between  a shock  in  water 
and  one  in  air,  and  between  a shock  delivered  with  greater  exertion 
on  the  part  of  the  animal  and  one  with  less,  seemed  to  determine, 
that  the  charge  of  his  organs  with  electricity  was  effected  in  an 
instant,  as  well  as  the  discharge. 

The  torpedo  was  then  put  into  a flat  basket,  open  at  top,  but 
secured  by  a net  with  wide  meshes,  and  in  this  confinement  was  let 
down  into  the  water  about  a foot  below  the  surface  : being  there 
touched  through  the  meshes  with  only  a single  finger  on  one  of  his 
electric  organs,  while  the  other  hand  was  held  at  a distance  in  the 
water,  he  gave  shocks  which  were  distinctly  felt  in  both  hands. 

The  circuit  for  the  passage  of  the  effect  being  contracted  to  the 
finger  and  thumb  of  one  hand,  applied  above  and  below  to  a single 
organ  produced  a shock,  to  our  sensation,  of  twice  the  force  of  that 
in  the  larger  circuit  by  the  arms. 

The  torpedo,  still  confined  in  the  basket,  being  raised  to  within 
three  inches  of  the  surface  of  the  water,  was  there  touched  with  a 
short  iron  bolt,  which  was  held  half  above  and  half  in  the  water  by 
one  hand,  while  the  other  hand  was  dipped  as  before  at  a distance 
in  the  water;  and  strong  shocks,  felt  in  both  hands,  were  thus  ob- 
tained through  the  iron. 

A wet  hempen  cord  being  fastened  to  the  iron  bolt,  was  held  in 
the  hand  above  water,  while  the  bolt  touched  the  torpedo;  and 
shocks  were  obtained  through  both  those  substances. 

A less  powerful  torpedo,  suspended  in  a small  net,  being  frequently 
dipped  into  water  and  raised  again,  gave  from  the  surface  of  the 
water  slight  shocks  through  the  net  to  the  person  holding  it. 

These  experiments  in  water  manifested  that  bodies  immersed  in 
that  element  might  be  affected  by  immediate  contact  with  the 
torpedo  ; that  the  shorter  the  circuit  in  which  the  electricity  moved, 
the  greater  would  be  the  effect ; and  that  the  shock  was  communica- 
ble from  the  animal  in  water  to  persons  in  air  through  some 
substances. 

How  far  harpoons  and  nets,  consisting  of  wood  and  hemp,  could 
in  like  circumstances,  as  it  has  been  frequently  asserted,  convey 
the  effect,  was  not  so  particularly  tried  as  to  enable  us  to  confirm 

35* 


402 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


it.  I mention  the  omission  in  the  hope  that  some  one  may  be  in- 
duced to  determine  the  point  by  express  trial. 

We  convinced  ourselves  on  former  occasions  that  the  accurate 
Ka3mpfer,*  who  so  well  describes  the  effect  of  the  torpedo,  and 
happily  compares  it  with  lightning,  was  deceived  in  the  circum- 
stance that  it  could  be  avoided  by  holding  in  the  breath,  which  we 
found  no  more  to  prevent  the  shock  of  the  torpedo  when  he  was 
disposed  to  give  it,  than  it  would  prevent  the  shock  of  the  Leyden 
phial. 

Several  persons,  foaming  as  many  distinct  circuits,  can  be  af- 
fected by  one  stroke  of  the  animal,  as  well  as  when  joined  in  a single 
circuit.  For  instance,  four  persons,  touching  separately  his  upper 
and  lower  surfaces,  were  all  affected  ; two  persons  likewise,  after 
the  electricity  had  passed  through  a wire  into  a basin  of  water, 
transmitted  it  from  thence,  in  two  distinct  channels,  as  their  sensa- 
tion convinced  them,  into  another  basin  of  water,  from  whence  it 
was  conducted,  probably  in  a united  state,  by  a single  wire.  How 
much  further  the  efiect  might  be  thus  divided  and  subdivided  into 
different  channels  was  not  determined  ; but  it  was  found  to  be  propor- 
tionably  weakened  by  multiplying  these  circuits,  as  it  had  been  by 
extending  the  single  circuit. 

Something  may  be  expected  to  be  said  of  the  parts  of  the  animal 
immediately  concerned  in  producing  the  electrical  effect.  The 
engraving  which  accompanies  this  letter,  while  it  shows  the  general 
figure  of  the  torpedo,  gives  an  internal  view  of  his  electric  organs. 
The  Society  will,  besides,  have  a full  anatomical  description  of 
these  parts  from  the  ingenious  Mr.  John  Hunter,  in  a paper  he  has 
expressly  written  on  the  subject  at  my  request.  It  would  there- 
fore be  superfluous  for  me  to  say  anything  either  in  regard  to  their 
situation  or  structure. 

I have  to  observe,  however,  that  in  these  double  organs  resides 
the  electricity  of  the  torpedo,  the  rest  of  his  body  appearing  to  be 
no  otherwise  concerned  in  his  electrical  effect  than  as  conducting 
it ; that  they  are  subject  to  the  will  of  the  animal ; but  whether, 
like  other  double  parts  so  controlable,  they  are  exercised  at  times 
singly  as  well  as  in  concert,  is  difficult  to  be  ascertained  by  experi- 
ment: that  their  upper  and  under  surfaces  are  capable,  from  a 
state  of  equilibrium  with  respect  to  electricity,  of  being  instantly 
thrown,  by  a mere  energy,  into  an  apposition  of  a flus  and  7nmus 
state,  like  that  of  the  charged  phial : that  when  they  are  thuscharged, 
the  upper  surfaces  of  the  two  are  in  the  same  state  of  electricity  ; 
as  are  the  under  surfaces  of  the  two,  though  in  a contrary  to  that 
of  the  upper;  for  no  shock  can  be  obtained  by  an  insulated  person 
touching  both  organs  above,  or  both  below  : and  that  the  produc- 
tion of  the  effect  depends  solely  on  an  intercourse  being  made  be- 
tween the  opposite  surfaces  of  the  organs,  whether  taken  singly 
or  jointly. 


Ksempf.  Amoen.  Exet.  1713,  p.  514. 


OF  THE  ELECTRIC  PROPERTY  OF  THE  TORPEDO. 


403 


All  the  parts  bordering  on  the  organs  act  more  or  less  as  con- 
ductors, either  through  their  substance  or  by  their  superficies. 
While  an  insulated  person,  placing  two  fingers  on  the  same  surface 
of  one  or  both  organs,  cannot  be  affected,  if  he  removes  one  of  his 
fingers  to  any  such  contiguous  part  he  wdll  be  liable  to  a shock  ; but 
this  shock  will  not  be  near,  perhaps  not  half  so  violent  as  one  taken 
immediately  between  the  opposite  surfaces  of  the  organ,  which 
shows  the  conduction  to  be  very  imperfect. 

The  parts  which  conduct  the  best  are  the  two  great  lateral  fins 
bounding  the  organs  outwardly,  and  the  space  lying  between  the 
two  organs  inwnirdly.  All  below  the  double  transverse  cartilages 
scarcely  conduct  at  all,  unless  when  the  fish  is  just  taken  out  of 
water  and  is  still  wet,  the  mucus  with  which  he  is  lubricated  show-- 
ing  itself  as  it  dries  to  be  of  an  insulating  nature. 

The  organs  themselves  when  uncharged  appeared  to  be,  not  in- 
teriorly we  might  suppose,  but  rather  exteriorly,  conductors  of  a 
shock.  An  insulated  person  touching  two  torpedos,  lying  near  one 
another  on  a damp  table,  with  fingers  placed,  one  on  the  organ  of 
one  fish,  and  another  on  the  organ  of  the  other,  was  sensible  of 
shocks,  sometimes  delivered  by  one  fish,  and  sometimes  by  the  other, 
as  might  be  discovered  by  the  respective  winking  of  their  eyes. 
That  the  organs  uncharged  served  some  way  or  other  as  conductors, 
was  confirmed  with  artificial  electricitv,  in  passing  shocks  by  them, 
and  in  taking  sparks  from  them  when  electrified. 

The  electric  eflect  was  never  perceived  by  us  to  be  attended 
wdth  any  motion  or  alteration  in  the  organs  themselves,  but  was 
frequently  accompanied  with  a little  transient  agitation  along  the 
cartilages  which  surround  both  organs:  this  is  not  discernible  in  the 
plump  and  turgid  state  of  the  animal  while  he  is  fresh  and  vigorous  : 
but  as  his  force  decays,  from  the  relaxation  of  his  muscles,  his  car- 
tilages appear  through  the  skin,  and  then  the  slight  action  along 
them  is  discovered. 

May  we  not  from  all  these  premises  conclude,  that  the  effect  of 
the  torpedo  proceeds  from  a modification  of  the  electric  fluid  I 
The  torpedo  resembles  the  charged  phial  in  that  characteristic 
point  of  a reciprocation  between  its  two  surfaces.  Their  effects 
are  transmitted  by  the  same  mediums;  than  which  there  is  not  per- 
haps a surer  criterion  to  determine  the  identity  of  subtile  matter: 
they  besides  occasion  the  same  impression  on  our  nerves.  Like 
effects  have  like  causes.  But  it  may  be  objected,  that  the  effects 
of  the  torpedo,  and  of  the  charged  phial,  are  not  similar  in  all  their 
circumstances  ; that  the  charged  phial  occasions  attractive  or  re- 
pulsive dispositions  in  neighbouring  bodies  ; and  that  its  discharge 
is  obtained  through  a portion  of  air,  and  is  accompanied  with  light 
and  sound  ; nothing  of  which  occurs  with  respect  to  the  torpedo. 

The  inaction  of  the  electricity  of  the  animal  in  these  particulars, 
whilst  its  elastic  force  is  so  great  as  to  transmit  the  effect  through 
an  extensive  circuit  and  in  its  course  to  communicate  a shock, 
may  be  a new  phsenomenon,  but  is  no  ways  repugnant  to  the  laws 


404 


HUNTER  ON  THE  ANIMAL  OECONOMY. 


of  electricity,  for  here  too  the  operations  of  the  animal  may  be 
imitated  by  art. 

The  same  quantity  of  electric  matter,  according  as  it  is  used  in 
a dense  or  rare  state,  will  produce  the  different  consequences. 
For  example,  a small  phial,  whose  coated  surface  measures  only 
six  square  inches,  will,  on  being  highly  charged,  contain  a dense 
electricity  capable  of  forcing  a passage  through  an  inch  of  air,  and 
afford  the  phaenomena  of  light,  sound,  attraction,  and  repulsion. 
But  if  the  quantity  condensed  in  this  phial  be  made  rare  by  com- 
municating it  to  three  large  connected  jars,  whose  coated  surfaces 
shall  form  together  an  area  four  hundred  times  larger  than  that  of 
the  phial  (I  instance  these  jars  because  they  are  such  as  I use) ; it 
will,  thus  dilated,  yield  all  the  negative  phaenomena,  if  I may  so 
call  them,  of  the  torpedo ; it  will  not  now  pass  the  hundredth  part 
of  that  inch  of  air  which  in  its  condensed  state  it  sprung  through 
with  ease ; it  will  now  refuse  the  minute  intersection  in  the  strip  of 
tinfoil;  the  spark  and  its  attendant  sound,  even  the  attraction  or 
repulsion  of  light  bodies,  will  now  be  wanting;  nor  will  a point 
brought  however  near,  if  not  in  contact,  be  able  to  draw  off  the 
charge:  and  yet,  with  this  diminished  elasticity,  the  electric  matter 
will,  to  effect  its  equilibrium,  instantly  run  through  a considerable 
circuit  of  different  conductors,  perfectly  continuous,  and  make  us 
sensible  of  an  impulse  in  its  passage. 

Let  me  here  remark,  that  the  sagacity  of  Mr.  Cavendish  in 
devising  and  his  address  in  executing  electrical  experiments,  led 
him  the  first  to  experience  with  artificial  electricity,  that  a shock 
could  be  received  from  a charge  which  was  unable  to  force  a pas- 
sage through  the  least  space  of  air. 

But  after  the  discovery  that  a large  area  of  rare  electricity 
would  imitate  the  effect  of  the  torpedo,  it  may  be  inquired,  where 
is  this  large  area  to  be  found  in  the  animal  ? We  here  approach  to 
that  veil  of  nature  which  man  cannot  remove.  This,  however,  we 
know,  that  from  infinite  division  of  parts  infinite  surface  may  arise, 
and  even  our  gross  optics  tell  us  that  those  singular  organs,  so 
often  mentioned,  consist  like  our  electric  batteries  of  many  vessels, 
call  them  cylinders  or  hexagonal  prisms,  whose  superficies  taken 
together  furnish  a considerable  area. 


37.  ANATOMICAL  OBSERVATIONS  ON  THE  TORPEDO.* 

BY  JOHN  HUNTER,  F.R.S. 

I WAS  desired  some  time  since,  by  Mr.  Walsh,  whose  experi- 
ments at  La  Rochelle  had  determined  the  effect  of  the  torpedo  to 

* [This  paper  was  read  before  the  Royal  Society  July  1,  1773,  and  published 
in  the  63d  volume  of  the  Philosophical  Transactions.] 


ANATOMICAL  OBSERVATIONS  ON  THE  TORPEDO. 


405 


be  electrical,  to  dissect  and  examine  the  peculiar  organs  by  which 
that  animal  produces  so  extraordinary  an  effect.  This  I have  done 
in  several  subjects  furnished  to  me  by  that  gentleman. 

I am  now  desired  by  him  to  lay  before  the  Society  the  observa- 
tions I have  made ; and  for  the  better  understanding  of  them,  to 
present,  on  his  part,  a male  and  female  torpedo  in  spirits;  in  the 
latter  of  which  the  electric  organs  are  exposed  in  different  views 
and  sections;  likewise  a copper-plate,  which  he  took  care  to  have 
engraved,  exhibiting  those  organs. 

Of  the  general  structure  and  anatomy  of  the  torpedo  I say 
nothing,  since  the  animal  does  not  differ  very  materially,  excepting 
in  its  electric  organs  (as  they  have  been  properly  named  by  Mr. 
Walsh),  from  the  rest  of  the  rays,  of  which  family  it  is  well  known 
to  be.  I will  only  premise  that  the  torpedo,  of  which  I treat,  is 
about  eighteen  inches  long,  twelve  broad,  and  it)  its  central  or 
thickest  part  two  inches  thick  ; which  is  nearly  the  size  of  the 
female  specimen  now  presented  to  the  Society,  as  well  as  of  that 
from  which  the  plate  was  taken  : but  where  there  is  any  difference 
in  the  organ  ai’ising  from  difference  in  size,  notice  will  be  taken  of 
it  in  this  account. 

The  electric  organs  of  the  torpedo  ai’e  placed  on  each  side  of  the 
cranium  and  gills,  reaching  from  thence  to  the  semicircular  carti- 
lages of  each  great  fin,  and  extending  longitudinally  from  the 
anterior  extremity  of  the  animal  to  the  transverse  cartilage  which 
divides  the  thorax  from  the  abdomen;  and  within  these  limits  they 
occupy  the  whole  space  between  the  skin  of  the  upper  and  of  the 
under  surfaces:  they  are  thickest  at  the  edges  near  the  centre  of 
the  fish,  and  become  gradually  thinner  towards  the  extremities. 
Each  electric  organ,  at  its  inner  longitudinal  edge,  is  unequally 
hollowed,  being  exactly  fitted  to  the  irregular  projection  of  the  cra- 
nium and  gills.  The  outer  longitudinal  edge  is  a convex  elliptic 
curve.  The  anterior  extremity  of  each  organ  makes  the  section  of 
a small  circle  ; and  the  posterior  extremity  makes  nearly  a right 
angle  with  the  inner  edge.  Each  organ  is  attached  to  the  sur- 
rounding parts  by  a close  cellular  membrane,  and  also  by  short 
and  strong  tendinous  fibres  which  pass  directly  across  from  its 
outer  edge  to  the  semicircular  cartilages. 

They  are  covered  above  and  below  by  the  common  skin  of  the 
animal,  under  which  there  is  a thin  fascia  spread  over  the  whole 
organ.  This  is  composed  of  fibres,  which  run  longitudinally,  or  in 
the  direction  of  the  body  of  the  animal  : these  fibres  appear  to  be 
perforated  in  innumerable  places,  which  gives  the  fascia  the 
appearance  of  being  fasciculated  ; its  edges  all  around  are  closely 
connected  to  the  skin,  and  at  last  appear  to  be  lost,  or  to  degenerate 
into  the  common  cellular  membrane  of  the  skin. 

Immediately  under  this  is  another  membrane  exactly  of  the  same 
kind,  the  fibres  of  which  in  some  measure  decussate  those  of  the 
former,  passing  from  the  middle  line  of  the  body  outwards  and 
backwards.  The  inner  edge  of  this  is  lost  with  the  first  described ; 


406 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  anterior,  outer,  and  posterior  edges  are  partly  attached  to  the 
semicircular  cartilages,  and  partly  lost  in  the  common  cellular 
membrane. 

This  inner  fascia  appears  to  be  continued  into  the  electric  organ 
by  so  many  processes,  and  thereby  makes  the  membranous  sides 
or  sheaths  of  the  columns,  which  are  presently  to  be  described ; 
and  between  these  processes  the  fascia  covers  the  end  of  each 
column,  making  the  outermost  or  first  partition. 

Each  organ  of  the  fish  under  consideration*  is  about  five  inches 
in  length,  and  at  the  anterior  end  three  in  breadth,  though  it  is  but 
little  more  than  half  as  broad  as  at  the  posterior  extremity. 

Each  consists  wholly  of  perpendicular  columns,  reaching  from 
the  upper  to  the  under  surface  of  the  body,  and  varying  in  their 
lengths  according  to  the  thickness  of  the  parts  of  the  body  where 
they  are  placed;  the  longest  column  being  about  an  inch  and  a 
half,  the  shortest  about  one-fourth  of  an  inch  in  length,  and  their 
diameters  about  two-tenths  of  an  inch. 

The  figures  of  the  columns  are  very  irregular,  varying  accord- 
ing to  situation  and  other  circumstances.  The  greatest  number  of 
them  are  either  irregular  hexagons  or  irregular  pentagons ; but 
from  the  irregularity  of  some  of  them  it  happens  that  a pretty 
regular  quadrangular  column  is  sometimes  formed.  Those  of  the 
exterior  row  are  either  quadrangular  or  hexagonal,  having  one 
side  external,  two  lateral,  and  either  one  or  two  internal.  In  the 
second  row  they  are  mostly  pentagons. 

Their  coats  are  very  thin,  and  seem  transpai’ent,  closely  connected 
with  each  other,  having  a kind  of  loose  network  of  tendinous 
fibres,  passing  transversely  and  obliquely  between  the  columns,  and 
uniting  them  more  firmly  together.  These  are  mostly  observable 
where  the  large  trunks  of  the  nerves  pass.  The  columns  are  also 
attached  by  strong  inelastic  fibres,  passing  directly  from  one  to  the 
other. 

The  number  of  columns  in  different  torpedos  of  the  size  of  that 
now  offered  to  the  Society  appeared  to  be  about  470  in  each  organ, 
but  the  number  varies  according  to  the  size  of  the  fish.f  These 
columns  increase,  not  only  in  size,  but  in  number,  during  the  growth 
of  the  animal ; new  ones  forming  perhaps  every  year  on  the  ex- 
terior edges,  as  there  they  are  much  the  smallest.  This  process 
may  be  similar  to  the  formation  of  new  teeth  in  the  human  jaw  as  it 
increases.  ' 

Each  column  is  divided  by  horizontal  partition  placed  over 
each  other,  at  very  small  distances,  and  forming  numerous  inter- 
stices, which  appear  to  contain  a fluid.  These  partitions  consist  of 
a very  thin  membrane,  considerably  transparent.  Their  edges  ap- 
pear to  be  attached  to  one  another,  and  the  whole  is  attached  by 

* [This  specimen  was  eighteen  inches  long,  twelve  inches  broad,  and  in  its 
central  or  thickest  part  two  inches  thick.] 

I In  a very  large  Torpedo,  (see  the  preparation  No.  2176,  Physiological  Series,) 
the  number  of  columns  in  one  electric  organ  were  1182. 


ANATOMICAL  OBSERVATIONS  ON  THE  TORPEDO. 


407 


a fine  cellular  membrane  to  the  inside  of  the  columns.  They  are 
not  totally  detached  from  one  another:  I have  found  them  adhering 
at  different  places  by  blood-vessels  passing  from  one  to  another. 

The  number  of  partitions  contained  in  a column  of  one  inch  in 
length,  of  a torpedo  which  had  been  preserved  in  proof  spirit,  ap- 
peared on  a careful  examination  to  be  one  hundred  and  fifty;  and 
this  number  in  a given  length  of  column  appears  to  be  common  to 
all  sizes  in  the  same  state  of  humidity,  for  by  drying  they  may 
be  greatly  altered ; whence  it  appears  probable  that  the  increase 
in  the  length  of  a column,  during  the  growth  of  the  animal,  does 
not  enlarge  the  distance  between  each  partition  in  proportion  to 
that  growth;  but  that  new  partitions  are  formed,  and  added  to  that 
extremity  of  the  column  from  the  fascia. 

The  partitions  are  very  vascular;*  the  arteries  are  branches 
from  the  vessels  of  the  gills  which  convey  the  blood  that  has  re- 
ceived the  influence  of  respiration.  They  pass  along  with  the 
nerves  to  the  electric  organ,  and  enter  with  them  ; then  they  ramify 
in  every  direction  into  innumerable  small  branches  upon  the  sides 
of  the  columns,  sending  in  from  the  circumference  all  around  upon 
each  partition  small  arteries,  which  ramify  and  anastomose  upon  it, 
and  passing  also  from  one  partition  to  another,  anastomose  with  the 
vessels  of  the  adjacent  partitions. 

The  veins  of  the  electric  organ  pass  out  close  to  the  nerves  and 
run  between  the  gills  to  the  auricle  of  the  heart. 

The  nerves  inserted  into  each  electric  organ  arise  by  three  very 
large  trunks  from  the  lateral  and  posterior  part  of  the  brain.  The 
first  of  these  in  its  passage  outwards  turns  round  a cartilage  of  the 
cranium  and  sends  a few  branches  to  the  first  gill,  and  to  the  ante- 
rior part  of  the  head,  and  then  passes  into  the  organ  towards  its 
anterior  extremity.!  The  second  trunk  enters  the  giils  between 
the  first  and  second  openings,  and  after  furnishing  it  with  small 
branches  passes  into  the  organ  near  its  middle.  The  third  trunk, 
after  leaving  the  skull,  divides  itself  into  two  branches,  which  pass 
to  the  electric  organ  through  the  gills;  one  between  the  second  and 

* [See  prep.  2176,  which  is  the  section  of  a Torpedo,  of  very  large  size,  taken 
in  Torbay  in  August,  1774.  It  weighed  fifty-three  pounds,  was  four  feet  in 
length,  two  feet  and  a half  in  breadth,  and  four  inches  and  a half  in  thickness. 
IMr.  Hunter  having  received  this  fish  in  a recent  state  was  enabled  to  inject  it,  and 
thus  demonstrate  the  vascularity  of  the  electrical  organs.] 

t [This  nerve  is  a part  of  the  third  division  of  the  fifth  pair,  and  does  not 
greatly  exceed  the  size  of  the  corresponding  nerve  in  other  species  of  the  ray 
tribe;  it  distributes  branches  to  the  mucous  tubes,  which  are  fewer  in 
number  in  the  torpedo  than  in  the  ordinary  rays,  before  it  penetrates  the  electric 
organ.  The  other  great  fasciculi  of  nerves  correspond  with  the  pneumogastric, 
or  eighth  pair  of  nerves  ; a large  branch  is  continued  from  the  most  posterior  to 
the  stomach,  where  it  is  spread  over  the  great  arch.  Dr.  .lohn  Davy  conjectures 
that  the  superfluous  electricity  when  not  required  for  the  defence  of  the  animal 
may  be  directed  to  this  organ  to  promote  digestion.  In  the  instance  of  a Torpedo 
which  he  preserved  alive  for  many  days,  and  which  was  frequently  excited  to 
give  shocks,  digestion  appeared  to  have  been  completely  arrested  ; when  it  died, 
a small  fish  was  found  in  its  stomach,  much  in  the  same  state  in  which  it  was 
swallowed  ; no  portion  of  it  had  been  dissolved.] 


408 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


third  openings,  the  other  between  tlie  third  and  fourth,  giving  small 
branches  to  the  gills  itself.  These  nerves  having  entered  the  organs 
ramify  in  every  direction  between  the  columns,  and  send  in  small 
branches  upon  each  partition,  where  they  are  lost. 

The  magnitude  and  the  number  of  the  nerves  bestowed  on  these 
organs,  in  proportion  to  their  size,  must  on  reflection  appear  as  ex- 
traordinary as  the  phenomena  tliey  aflbrd.  Nerves  are  given  to 
parts  either  for  sensation  or  action.  Now  if  we  except  the  more 
important  senses  of  seeing,  hearing,  smelling,  and  tasting,  which  do 
not  belong  to  the  electric  organs,  there  is  no  part  even  of  the  most 
perfect  animal  wliich,  in  proportion  to  its  size,  is  so  liberally  sup- 
plied with  nerves  ; nor  do  the  nerves  seem  necessary  for  any  sen- 
sation which  can  be  supposed  to  belong  to  the  electric  organs. 
And  with  respect  to  action,  there  is  no  part  of  any  animal  with 
which  I am  acquainted,  however  strong  and  constant  its  natural 
actions  may  be,  which  has  so  great  a proportion  of  nerves. 

If  it  be  then  probable  that  no  nerves  are  not  necessary  for  the 
purposes  of  sensation  or  action,  may  we  not  conclude  that  they  are 
subservient  to  the  formation,  collection,  or  management  of  the  elec- 
tric fluid  I especially  as  it  appears  evident,  from  Mr.  Walsh’s  ex- 
periments, that  the  will  of  the  animal  does  absolutely  control  the 
electric  powers  of  its  body,  which  must  depend  on  the  energy  of  the 
nerves. 

How  far  this  may  be  connected  with  the  powers  of  the  nerves  in 
general,  or  how  far  it  may  lead  to  an  explanation  of  their  opera- 
tions, time  and  future  discoveries  alone  can  fully  determine. 


38.  AN  ACCOUNT  OF  THE  GYMNOTUS  ELECTRICUS.* 

BY  JOHN  HUNTER,  F.  R.  S. 

To  Mr.  Walsh,  the  first  discoverer  of  animal  electricity,  the 
learned  will  be  indebted  for  whatever  the  following  pages  may  con- 
tain, either  curious  or  useful.  The  specimen  of  the  animal  which 
they  describe  was  procured  by  that  gentleman,  and  at  his  request 
this  dissection  was  performed  and  this  account  of  it  is  communi- 
cated. 

This  fish  on  the  first  view  appears  very  much  like  an  eel,  from 
which  resemblance  it  has  most  probably  got  its  name  ; but  it  has 
none  of  the  specific  properties  of  that  fish.  This  animal  may  be 
considered,  both  anatomically  and  physiologically,  as  divided  into 
two  parts,  viz.,  the  common  animal  part,  and  a part  which  is  super- 
added,  viz.  the  feculiar  organ.  I shall  at  present  consider  it  only 
with  respect  to  the  last,  as  the  first  explains  nothing  relating  to  the 

* [This  paper  was  read  before  the  Royal  Society  May  11,  1775,  and  published 
in  the  65th  volume  of  the  Philosophical  Transactions.] 


AN  ACCOUNT  OF  THE  GYMNOTUS  ELECTKICUS. 


409 


other,  nor  anything  relating  to  the  animal  oeconomy  of  fish  in  gene- 
ral. The  first,  or  common  animal  part,  is  so  contrived  as  to  ex- 
ceed what  was  necessary  for  itself,  in  order  to  give  situation,  nou- 
rishment, and  most  probably  the  peculiar  property  to  the  second. 
The  last  part,  or  peculiar  organ,  has  an  immediate  connexion  with 
the  first,  the  body  affording  it  a situation,  the  heart  nourishment,  and 
the  brain  nerve,  and  probably  its  peculiar  powers.  For  the  first  of 
these  purposes  the  body  is  extended  out  in  length,  being  much 
longer  than  would  be  sufficient  for  what  may  be  called  its  progres- 
sive motion.  For  the  real  body,  or  that  part  where  the  viscera 
and  parts  of  generation  lie,  is  situated,  with  respect  to  the  head,  as 
in  other  fish,  and  is  extremely  short,  so  that,  according  to  the  ordi- 
nary proportions,  this  should  be  a very  short  fish.  Its  great  length, 
therefore,  seems  chiefly  intended  to  afford  the  surface  for  the  sup- 
port of  the  peculiar  organ  ; however,  the  tail  part  is  likewise  adapt- 
ed to  the  progressive  motion  of  the  whole  and  to  preserve  the 
specific  gravity  ; for  the  spine,  medulla  spinalis,  muscles,  fin,  and 
air-bladder*  are  continued  through  its  whole  length.  Besides  which 
parts  there  is  a membrane  passing  from  the  spine  to  that  fin  which 
runs  along  the  belly  or  lower  edge  of  the  animal.  This  membrane 
is  broad  at  the  end  next  to  the  head,  terminating  in  a point  at  the 
tail ; it  is  a support  for  the  abdominal  fin,  gives  a greater  surface 
of  support  for  the  organ,  and  makes  a partition  between  the  organs 
of  the  two  opposite  sides. 


The  Organs, 

The  organs  which  produce  the  peculiar  effect  of  this  fish  con- 
stitute nearly  one-half  of  that  part  of  the  flesh  in  which  they  are 
placed,  and  perhaps  make  more  than  one-third  of  the  whole  animal. 
There  are  two  pair  of  these  organs,  a larger  and  smaller,  one  being 
placed  on  each  side.  The  large  pair  occupy  the  whole  lower  or 
anterior,  and  also  the  lateral  part  of  the  body,  making  the  thick- 
ness of  the  fore  or  lower  parts  of  the  animal ; and  run  almost 
through  its  whole  length,  viz.,  from  the  abdomen  to  near  the  end  of 
the  tail.  It  is  broadest  on  the  sides  of  the  fish  at  the  anterior  end, 
where  it  incloses  more  of  the  lateral  parts  of  the  body,  becomes 
narrower  towards  the  end  of  the  tail,  occupying  less  and  less  of  the 
sides  of  the  animal,  till  at  last  it  ends  almost  in  a point.  These  two 
organs  are  separated  from  one  another  at  the  upper  part  by  the 
muscles  of  the  back  which  keep  their  posterior  or  upper  edges  at  a 
considerable  distance  from  one  another  ; below  that,  and  towards 
the  middle,  they  are  separated  by  the  air-bag,  and  at  their  lower 
parts  they  are  separated  by  the  middle  partition.  They  begin  for- 

* [The  Gymnotus  electricus  has  two  air-bladders,  one  of  which,  of  an  oval  form 
and  bilobed,  is  situated  at  the  anterior  part  of  the  abdomen,  beneath  the  oeso- 
phagus; the  other  is  the  elongated  sac  described  by  Hunter,  and  extended 
through  the  posterior  part  of  the  body.  In  another  species,  the  Gymnotus  asqui- 
labiatus  of  Humboldt,  the  posterior  elongated  air-bladder  is  wanting.] 

36 


410 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


wards  by  a pretty  regular  edge,  almost  at  right  angles  with  the 
longitudinal  axis  of  the  body,  situated  on  the  lower  and  lateral  parts 
of  the  abdomen.  Their  upper  edge  is  a pretty  straight  line,  with 
small  indentations  made  by  the  nerves  and  blood-vessels  which 
pass  round  it  to  the  skin.  At  the  anterior  end  they  go  as  far  to- 
wards the  back  as  the  middle  line  of  the  animal,  but  in  their  ap- 
proach towards  the  tail  they  gradually  leave  tliat  line,  coming 
nearer  to  the  lower  surface  of  the  animal.  The  general  shape  of  the 
organ,  on  an  external  or  side  view,  is  broad  at  the  end  next  to  the 
head  of  the  animal,  becoming  gradually  narrower  towards  the  tail, 
and  ending  there  almost  in  a point.  The  other  surfaces  of  the 
organ  are  fitted  to  the  shape  of  the  parts  with  which  they  come  in 
contact,  therefore  on  the  upper  and  inner  surface  it  is  hollowed  to 
receive  the  muscles  of  the  back.  There  is  also  a longitudinal 
depression  on  its  lower  edge,  where  a substance  lies  which  divides 
it  from  tiie  small  organ,  and  which  gives  a kind  of  fixed  point  for 
the  lateral  muscles  of  the  fin.  Its  most  internal  surface  is  a plane 
adapted  to  the  partition  which  divides  the  two  organs  from  one 
another.  The  edge  next  to  the  muscles  of  the  back  is  very  thin, 
but  the  organ  becomes  thicker  and  thicker  towards  the  middle, 
where  it  approaches  the  centre  of  the  animal.  It  becomes  thinner 
again  towards  the  lower  surface  or  belly,  but  that  edge  is  not  so 
thin  as  the  other.  Its  union  with  the  parts  to  which  it  is  attached 
is  in  general  by  a loose  but  pretty  strong  cellular  membrane,  except 
at  the  partition,  to  which  it  is  joined  so  close  as  to  be  almost  inse- 
parable. 

The  small  organ  lies  along  the  lower  edge  of  the  animal,  nearly 
to  the  same  extent  as  the  other.  Its  situation  is  marked  externally  by 
the  muscles  which  move  the  fin  under  wdiich  it  lies.  Its  anterior 
end  begins  nearly  in  the  same  line  with  the  large  organ,  and  just 
where  the  fin  begins.  It  terminates  almost  insensibly  near  the  end 
of  the  tail,  where  the  large  organ  also  terminates.  It  is  of  a trian- 
gular figure,  adapting  itself  to  the  part  in  which  it  lies.  Its  anterior 
end  is  the  narrow’est  part ; towards  the  tail  it  becomes  broader  ; in 
the  middle  of  the  organ  it  is  thickest,  and  from  thence  becomes 
gradually  thinner  to  the  tail,  where  it  is  very  thin.  The  two  small 
organs  are  separated  from  one  another  by  the  middle  muscles,  and 
by  the  bones  upon  which  the  bones  of  the  fins  are  articulated.  The 
large  and  the  small  organ  on  each  side  are  separated  from  one 
another  by  a fatty  membrane,  the  inner  edge  of  which  is  attached 
to  the  middle  partition,  and  its  outer  edge  is  lost  on  the  skin  of  the 
animal.  To  expose  the  large  organ  to  view  nothing  more  is  neces- 
sary than  to  remove  the  skin,  which  adheres  to  it  by  a loose  cellular 
membrane;  but  to  expose  the  small  organ  it  is  necessary  to  remove 
the  lonst  row  of  small  muscles  which  move  the  fin. 

Of  the  Structure  of  these  Organs. 

The  structure  is  extremely  simple  and  regiilar,  consisting  of  two 
parts,  viz.,  flat  partitions  of  septa,  and  cross  divisions  betw’een  them. 


AN  ACCOUNT  OF  THE  GYMNOTUS  ELECTRICUS. 


411 


The  outer  edges  of  these  septa  appear  externally  in  parallel  lines 
nearly  in  the  direction  of  the  longitudinal  axis  of  the  body.  These 
septa  are  thin  membranes,  placed  nearly  parallel  to  one  another. 
Their  lengths  are  nearly  in  the  direction  of  the  long  axis,  and  their 
breadth  is  nearly  the  semi-diameter  of  the  body  of  the  animal, 
they  are  of  different  lengths,  some  being  as  long  as  the  whole  organ. 
I shall  describe  them  as  beginning  principally  at  the  anterior  end 
of  the  organ,  although  a few  begin  along  the  upper  edge,  and  the 
whole,  passing  towards  the  tail,  gradually  terminate  on  the  lower 
surface  of  the  organ ; the  lowermost  at  their  origin  terminating 
soonest.  Their  breadths  differ  in  different  parts  of  the  organ. 
They  are  in  general  broadest  near  the  anterior  end,  answering  to 
the  thickest  part  of  the  organ,  and  become  gradually  narrower  to- 
wards the  tail;  however,  they  are  very  narrow  at  their  beginnings 
or  anterior  ends.  Those  nearest  to  the  muscles  of  the  back  are  the 
broadest,  owing  to  their  curved  or  oblique  situation  upon  these 
muscles,  and  grow  gradually  narrower  towards  the  lower  part, 
which  is  in  a great  measure  owing  to  their  becoming  more  trans- 
verse, and  also  to  the  organ  becoming  thinner  at  that  place.  They 
have  an  outer  and  an  inner  edge;  the  outer  is  attached  to  the  skin 
of  the  animal,  to  the  lateral  muscles  of  the  fin,  and  to  the  membrane 
which  divides  the  great  organ  from  the  small,  and  the  whole  of 
their  inner  edges  are  fixed  to  the  middle  partition  formerly  described, 
also  to  the  air-bladder,  and  three  or  four  terminate  on  that  surface 
which  inclose  the  muscles  of  the  back.  These  septa  are  at  the 
greatest  distance  from  one  another  at  their  exterior  edges  near  the 
skin,  to  which  they  are  united  ; and  as  they  pass  from  the  skin  to- 
wards their  inner  attachments  they  approach  one  another.  Some- 
times we  find  two  uniting  into  one.  On  that  side  next  to  the  mus- 
cles of  the  back  they  are  hollow  from  edge  to  edge,  answering  to 
the  shape  of  those  muscles,  but  become  less  and  less  so  towards 
the  middle  of  the  organ,  and  from  that  towards  the  lower  part  of 
the  organ  they  become  curved  in  the  other  direction.  At  the  an- 
terior part  of  the  large  organ,  where  it  is  nearly  of  an  equal  breadth, 
they  run  pretty  parallel  to  one  another,  and  also  pretty  straight, 
but  where  the  organ  becomes  narrower  it  may  be  observed  in  some 
places  that  two  join  or  unite  into  one,  especially  where  a nerve 
passes  across.  The  termination  of  this  organ  at  the  tail  is  so  very 
small  that  I could  not  determine  whether  it  consisted  of  one  septum 
or  more.  The  distances  between  these  septa  will  differ  in  fishes 
of  different  sizes.  In  a fish  of  two  feet  four  inches  in  length  I found 
them  2V  of  an  inch  distant  from  one  another,  and  the  breadth  of 
the  whole  organ,  at  the  broadest  part,  about  an  inch  and  a quarter, 
in  which  place  were  thirty-four  septa.  The  small  organ  has  the 
same  kind  of  septa,  in  length  passing  from  end  to  end  of  the  organ, 
and  in  breadth  passing  quite  across;  they  run  somewhat  serpen- 
tine, not  exactly  in  straight  lines.  Their  outer  edges  terminate  on 
the  outer  surface  of  the  organ,  which  is  in  contact  with  the  inner 
surface  of  the  external  muscle  of  the  fin,  and  their  inner  edges  are 


412 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


in  contact  with  the  centre  muscles.  They  differ  very  much  in 
breadth  from  one  another,  the  broadest  being  equal  to  one  side  of 
the  triangle,  and  the  narrowest  scarcely  broader  than  the  point  or 
edge.  They  are  pretty  nearly  at  equal  distances  from  one  another, 
but  much  nearer  than  those  of  the  large  organ,  being  only  about 
part  of  an  inch  asunder  ; but  they  are  at  a greater  distance  from  one 
another  towards  the  tail,  in  proportion  to  the  increase  of  breadth 
of  the  organ.  The  organ  is  about  half  an  inch  in  breadth,  and  has 
fourteen  septa.  These  septa,  in  both  organs,  are  very  tender  in 
consistence,  being  easily  torn.  They  appear  to  answer  the  same 
purpose  w'ith  the  columns  in  the  torpedo,  making  walls  or  butments 
for  the  subdivisions,  and  are  to  be  considered  as  making  so  many 
distinct  organs.  These  septa  are  intersected  transversely  by  very 
thin  plates  or  membranes,  whose  breadth  is  the  distance  between 
any  two  septa,  and  therefore  of  different  breadths  indifferent  parts, 
broadest  at  that  edge  which  is  next  to  the  skin,  narrowest  at  that 
next  to  the  centre  of  the  body,  or  to  the  middle  partition  which  di- 
vides the  two  organs  from  one  another.  Tlieir  lengths  are  equal  to 
the  breadths  of  the  septa,  between  which  they  are  situated. 
There  is  a regular  series  of  them  continued  from  one  end  of  any  two 
septa  to  the  other.  They  appear  to  be  so  close  as  even  to  touch. 
In  an  inch  in  length  there  are  about  two  hundred  and  forty,  which 
multiplies  the  surface  in  the  whole  to  a vast  extent. 

Of  the  Nerves. 

The  nerves  in  this  animal  may  be  divided  into  two  kinds,  the  first 
appropriated  to  the  general  purposes  of  life,  the  second  for  the 
management  of  this  peculiar  function,  and  very  probably  for  its  ex- 
istence. They  arise  in  general  from  the  brain  and  medulla  spinalis, 
as  in  other  fish,  but  those  from  the  medulla  are  much  larger  than  in 
fish  of  equal  size,  and  larger  than  is  necessary  for  the  common 
operations  of  life.  The  nerve  which  arises  from  the  brain  and  passes 
down  the  whole  length  of  the  animal  (which  I believe  exists  in  all 
fish)  is  larger  in  this  than  in  others  of  the  same  size,  and  passes 
nearer  to  the  spine.  In  the  common  eel  it  runs  in  the  muscles  of 
the  back,  about  midway  between  the  skin  and  spine.  In  the  cod  it 
passes  immediately  under  the  skin.  From  its  being  larger  in  this 
fish  than  in  others  of  the  same  size  one  might  suspect  that  it  was 
intended  for  supplying  the  organ  in  some  degree ; but  this  seems 
not  to  be  the  case,  as  I was  not  able  to  trace  any  nerves  going  from 
it  to  join  those  from  the  medulla  spinalis,  which  run  to  the  organ. 
This  nerve  is  as  singular  an  appearance  as  any  in  this  class  of 
animals  ; for  surely  it  must  appear  extraordinary  that  a nerve  should 
arise  from  the  brain  to  be  lost  in  common  parts  while  there  is  a 
medulla  spinalis  giving  nerves  to  the  same  parts.  It  must  still  re- 
main one  of  the  inexplicable  circumstances  of  the  nervous  system.* 

• [Th  is  remarkable  nerve,  the  nervus  lateralis,  is,  in  the  Gymnotus,  a branch 
of  the  nervus  vagus.  It  does  not  exist  in  the  myxine,  but  in  the  higher  car- 
tilaginous fishes  it  is  largely  developed.  In  the  rays  it  extends  from  the  occi- 
put to  the  end  of  the  tail,  even  where  this,  as  in  the  Baia  fasciata,  is  six  times 


AN  ACCOUNT  OF  THE  GYMNOTUS  ELECTRICUS. 


413 


The  organ  is  supplied  with  nerves  from  the  medulla  spinalis,  from 
which  they  come  out  in  pairs  between  all  the  vertebrae  of  the  spine. 
In  their  passage  from  the  spine  they  give  nerves  to  the  muscles  of 
the  back,  &c.  They  bend  forwards  and  outwards  upon  the  spine, 
between  it  and  the  muscles,  and  send  out  small  nerves  to  the  ex- 
ternal surface,  which  join  the  skin  near  to  the  lateral  lines.  These 
ramify  upon  the  skin,  but  are  principally  bent  forwards  between  it 
and  the  organ,  into  which  they  send  small  branches  as  the}'  pass 
along.  They  seem  to  be  lost  in  these  two  parts.  The  trunks  get 
upon  the  air-bladder,  or  rather  dip  between  it  and  the  muscles  of 
the  back,  and  continuing  their  course  forwards  upon  that  bag,  they 
dip  in  between  it  and  the  organ,  where  they  divide  into  smaller 
branches;  then  they  get  upon  the  middle  partition,  on  which  they 
continue  to  divide  into  still  smaller  branches;  after  which  they  pass 

the  length  of  the  body;  and  in  the  trunk  the  two  nerves  exceed  the  size  of  the 
spinal  chord. 

In  osseous  fishes  it  is  relatively  smaller,  and  in  some  species,  as  the  cod,  is 
formed  by  a combination  of  a branch  of  the  fifth  with  a filament  of  the  eighth  or 
nervus  vagus. 

Besides  the  class  of  fishes  (with  the  exception  of  the  myxine),  the  lateral 
nerve  is  also  present  in  those  reptiles  which  preserve  throughout  life  the  external 
branchiae  or  the  branchial  apertures,  and  which  reside  habitually  in  water,  and 
move,  like  fish,  by  the  actions  of  a caudal  fin.  In  the  Menobranchus  the  nervus 
lateralis  forms  a large  branch  of  the  nervus  vagus,  and  passes  superficially  be- 
neath the  skin  as  far  back  as  the  middle  of  the  tail,  where  it  joins  the  filaments 
of  the  spinal  nerves.  In  the  proteus  the  nervus  vagus  sends  off  on  each  side 
two  nervi  laterales,  one  deep-seated,  the  other  superficial.  In  the  menopome 
the  lateral  nerve  is  likewise  present,  hut  is  much  more  delicate  than  in  the 
Perennibranchiata  with  externa!  gills.  In  the  larva  of  the  Rana  paradoxa  the 
lateral  nerve  may  be  observed  beneath  the  skin  in  the  longitudinal  fissure  which 
separates  the  two  large  muscular  fasciculi  of  the  tail  on  each  side.  After  the 
full  formation  of  the  anterior  extremities  this  nerve  becomes  gradually  more 
attenuated,  and  finally  disappears  with  the  absorption  of  the  tail.  It  does  not 
exist  in  the  anourous  batrachia.  We  may  thus  perceive  a relationship  of  co- 
existence to  subsist  between  these  enigmatical  nerves  and  branchial  respiration. 
This  imperfect  kind  of  respiration  is  assisted  by  the  vascularity  and  active 
powers  of  excreting  mucus  in  the  whole  or  a part  of  the  external  tegument.  In 
the  osseous  fishes  a linear  series  of  mucous  follicles  is  extended  along  each  side 
of  the  body,  and  the  lateral  nerves,  which  run  parallel  with  these  lines  give 
numerous  branches  to  the  mucous  sacs  and  the  neighbouring  skin  ; and  in  the 
Perennibranchiata  the  lateral  nerves  are  exclusively  distributed  to  the  skin: 
hence  they  might  be  termed  the  cutaneous  respiratory  nerves.  4'hey  do  not  sup- 
ply the  muscles  along  which  they  pass:  these  derive  their  nervous  energy  from 
the  ordinary  spinal  nerves.  When  irritated  or  galvanized  the  lateral  nerves 
excite  no  contractions  in  the  muscles;  they  are  therefore  not  analogous  to  the 
spinal  accessory  nerves  in  the  mammalia.  In  the  Gpmnotus  Mr.  Hunter  was  not 
able  to  trace  any  nerves  going  from  the  lateral  nerve  to  join  those  from  the  me- 
dulla spinalis  which  supply  the  electric  organ,  but  it  anastomoses  with  the  spinal 
nerves  which  supply  the  caudal  fin.  And  in  the  cod,  where  this  anastomosis 
takes  place  at  each  of  the  numerous  fins,  Mr.  Swan  conjectures  that  its  function 
may  be  to  produce  sympath}'  and  harmonious  cooperation,  and  to  regulate  and 
produce,  independently  of  the  will,  the  action  of  the  muscles,  of  these  parts.  (See 
his  accurate  and  beautiful  Illustrations  of  the  Comparative  Anatomy  of  the 
Nervous  System,  p.  26,  pi.  vii.)  And  this  theory  equally  agrees  with  the  laws 
of  coexistence  of  the  lateral  nerves  as  established  by  an  extensive  induction  of 
particular  dissections.] 


36* 


414 


HUNTER  ON  THE  ANIMAL  GGCONOMY. 


on  and  get  upon  the  small  bones  and  muscles,  which  are  the  bases 
for  the  under  fin,  and  at  last  they  are  lost  on  that  fin.  After  having 
got  between  the  organ  and  the  above-mentioned  parts  they  are  con- 
stantly sending  small  nerves  into  the  organs,  first  into  the  great 
organ  and  then  into  the  small  one;  also  into  the  muscles  of  the  fin, 
and  at  last  into  the  fin  itself.  These  branches,  which  are  sent  into 
the  organ  as  the  trunk  passes  along,  are  so  small  that  I could  not 
trace  their  ramifications  in  the  organs.  In  this  fish,  as  well  as  in 
the  torpedo,  the  nerves  which  supply  the  organ  are  much  larger 
than  those  bestowed  on  any  other  part  for  the  purposes  of  sensation 
and  action;  but  it  appears  to  me  that  the  organ  of  the  torpedo  is 
supplied  with  much  the  largest  proportion.  If  all  the  nerves  which 
go  to  it  were  united  together  they  would  make  a vastly  greater 
chord  than  all  those  which  go  to  the  organ  of  this  eel.  Perhaps 
when  experiments  have  been  made  upon  this  fish,  equally  accurate 
with  those  made  upon  the  torpedo,  the  reason  for  this  difference 
may  be  assigned. 

Blood-  Vessels. 

How  far  this  organ  is  vascular  I cannot  positively  determine,  but 
from  the  quantities  of  small  arteries  going  to  it  I am  inclined  to 
believe  that  it  is  not  deficient  in  vessels.  The  arteries  arise  from 
the  large  artery  which  passes  down  the  spine  ; they  go  off  in  small 
branches  like  the  intercostals  in  the  human  subject,  pass  round  the 
air-bladder,  and  get  upon  the  partition  together  with  the  nerves, 
and  distribute  their  branches  in  the  same  manner’.  The  veins  take 
the  same  course  backwards,  and  enter  the  lai’ge  vein  which  runs 
parallel  with  the  artery. 


I A vivid  and  interesting  account  of  the  mode  of  capture  of  the  gymnotus, 
and  tire  power  of  its  electric  shocks,  is  given  by  Humboldt  in  his  Ob- 
servations de  Zoologie  et  d' Anatomie  Comparee,  vol.  i.,  p.  49.  An 
abstract  of  these  observations  will  be  found  in  the  Cyclopaedia  of  Anatomy 
and  Physiology,  art.  ‘Animal  Electricity,’  from  which,  towards  com- 
])leting  the  view  of  this  interesting  subject,  we  quote  the  following  descrip- 
tion of  the  electrical  organs  in  the  Silurus  or  Malaplerurus  electricus,  a 
fish  inhabiting  the  rivers  Nile  and  Niger. 

“ The  Electrical  Organs  in  the  Silurus. 

“ The  only  organ  that  can  be  regarded  as  connected  with  the  electrical 
function  in  this  fish  is  a thick  layer  of  dense  cellular  tissue,  which  com- 
j)letely  surrounds  the  body  immediately  beneath  the  integuments.  So 
compact  is  it  that  at  first  sight  it  might  be  mistaken  for  a deposit  of  fatty 
matter.  But  under  the  microscope  it  appears  to  be  composed  of  ten- 
dinous fibres,  closely  interwoven,  the  meshes  of  which  are  filled  with  a 
gelatinous  substance. 

“ This  organ  is  divided  by  a strong  aponeurotic  membrane  into  two 
circular  layers,  one  outer  lying  immediately  beneath  the  corion,  the  other 
internal,  placed  above  the  muscles. 


OBSERVATIONS  ON  BEES. 


415 


“ Both  organs  are  isolated  from  the  surrounding  parts  by  a dense  fascia, 
excepting  where  the  nerves  and  blood-vessels  enter.  The  cells  or  meshes 
in  the  outer  organ,  formed  by  its  reticulated  fibres,  are  rhombic  in  shape, 
and  very  minute,  so  as  to  require  a lens  to  see  them  well.  The  com- 
ponent tissue  of  the  inner  organ  is  somewhat  flaky,  and  also  cellular. 

“ The  nerves  of  the  outer  organ  are  branches  of  the  fifth  pair,  which 
runs  beneath  the  lateral  line,  and  above  the  aponeurotic  covering  of  the 
organ.  This  aponeurosis  is  pierced  with  many  holes  for  the  transmis- 
sion of  the  nerves,  which  are  lost  within  the  cellular  tissue  of  the  organ. 
The  intercostals  supply  the  inner  organ  : their  electrical  branches  are 
numerous,  and  remarkably  fine.  The  organs  of  the  other  known  elec- 
trical fishes  have  not  yet  come  under  the  notice  of  any  anatomist.  In 
taking  a general  view  of  these  interesting  organs,  we  are  struck  with  the 
existence  of  a certain  degree  of  analogy  amongst  them,  and  yet  we  fail  to 
discover  such  resemblances  as  miglit  be  expected,  and  such  as  exist 
between  the  structures  of  other  organs  performing  the  same  functions  in 
different  animals.  Here  we  have  tendinous  membranes  variously  arranged, 
yet  all  so  as  to  form  a series  of  separate  cells,  filled  with  a gelatinous 
matter.  But  how  great  is  the  difference  between  the  large  columnal  cell 
in  the  torpedo,  full  of  delicate  partitions,  and  the  minute  rhombic  cells  of 
the  silurus ! 

“ All,  however,  are  equally  supplied  with  nerves  of  very  great  size, 
larger  than  any  others  in  the  same  animals,  and  indeed  we  may  venture 
to  say,  larger  than  any  nerve  in  any  other  animal  of  like  bulk.  The 
organs  vary  in  different  fishes;  first,  in  situation,  relatively  to  other 
organs.  They  bound  the  sides  of  the  head  in  the  torpedo,  run  along  the 
tail  of  the  gyinnotus,  and  surround  the  body  of  the  silurus  : secondly,  in 
having  different  sources  of  nervous  energy  : and  thirdly,  in  the  form  of 
the  cells.  No  other  fishes  have  aponeuroses  so  extensive,  or  such  an 
accumulation  of  gelatin  and  albumen  in  any  cellular  organ.  Broussonet 
remarked  that  all  the  electrical  fishes  at  present  known  to  us,  although  all 
belonging  to  different  classes,  have  yet  certain  characters  in  common. 
All,  for  instance,  have  the  skin  smooth,  witiiout  scales,  thick,  and 
pierced  with  small  holes,  most  numerous  about  the  head,  and  which  pour 
out  a peculiar  fluid.  I'heir  fins  are  formed  of  soft  and  flexible  rays, 
united  by  means  of  dense  membranes.  Neither  the  gyinnotus  nor  tor- 
pedo has  any  dorsal  fin  ; the  silurus  has  only  a small  one  without  rays, 
situated  near  the  tail.  All  have  small  eyes.”] 


OBSERVATIONS  ON  BEES.* 

BY  JOHX  HUNTER,  F.R.S. 

Of  ihe  Common  Bee. 

The  common  bee,  from  a number  of  peculiarities  in  its  oeconomy, 
lias  called  forth  the  attention  of  the  curious,  and  from  the  profit 
arising  from  its  labours,  it  has  become  the  object  of  the  interested  ; 
therefore  no  wonder  it  has  excited  universal  attention,  even  from 

* [This  paper  was  read  before  the  Royal  Society,  February  23,  1792,  and  pub- 
lished in  the  82d  volume  of  the  Philosophical  Transactions.] 


416 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


the  savage  to  the  most  civilized  people;  but  it  has  hardly  been 
considered  by  the  anatomist,  at  least  the  tw'o  modes  of  investiga- 
tion have  not  gone  so  much  hand  in  hand  as  they  ought  to  have 
done. 

The  history  of  the  bee  has  rather  been  considered  as  a fit  subject 
for  the  curious  at  large,  whence  more  has  been  conceived  than 
observed.  Swammerdam,  indeed,  has  rather  erred  on  the  other 
side,  having  with  great  industry  been  veiy  minute  on  the  particular 
structure  of  the  bee.  I shall  liere  observe  that  it  is  commonly  not 
only  unnecessary  to  be  minute  in  our  description  of  parts  in  natural 
history,  but  in  general  improper.  It  is  unnecessary  when  it  does 
not  apply  to  anything  but  the  thing  itself,  more  especially  if  it  be  of 
no  consequence  ; but  whenever  it  applies,  then  it  should  so  far  be 
treated  accurately.  Minutiae  beyond  what  is  essential,  lire  the 
mind,  and  render  that  which  should  entertain  along  with  instruc- 
tion heavy  and  disagreeable  ; the  more  so  too  if  the  parts  are 
small,  where  the  sense  can  only  take  them  in  singly,  and  the  mind 
can  hardly  comprehend  the  whole  or  apply  all  the  parts  combined 
to  any  consequent  action.  This  has  been  too  much  the  case  with 
Swammerdam;  he  often  attempted  too  much  accuracy  in  his  de- 
scription of  minute  thing.*  But  the  natural  history  of  insects  has 
not  been  sufficiently  understood  at  large,  so  as  to  throw  light  on 
this  subject  where  there  was  an  analogy,  and  where  without  such 
analogy,  it  must  appear  in  the  bee  alone  unintelligible,  from  the 
obscurity'  attending  some  parts  of  their  oeconomy ; for  there  is 
hardly^  any  species  of  animals  but  what  has  some  part  of  its 
oeconomy  obscure,  and  probably^  this  is  as  much  so  in  this  insect 
as  in  any  other  class  of  animals  we  are  at  one  season  of  the  year 
almost  daily  seeing  ; yet  these  parts  of  the  ceconomy  may  be  evi- 
dent in  some  other  species  of  the  same  tribe  or  genus,  and  thus  be 
cleared  up,  from  analogy,  so  that  the  species  assist  each  other  in 
their  demonstration.  This  is  evident  in  the  whole  tribe  of  dying 
insects,  for  what  is  lost  or  cannot  be  made  out  in  the  one  may  be 
demonstrated  in  another  ; and  we  find  there  are  some  things  in  the 
oeconomy'  of  the  bee  that  cannot  be  seen  or  demonstrated  in  it 
alone,  but  which  are  evident  in  some  other  insects ; and  while  they 
possess  the  same  parts,  and  other  circumstances  are  similar,  we 
must  conclude  the  uses  of  those  parts  are  similar  in  both  ; for  when- 
ever a circumstance  in  one  animal  cannot  be  found  out  in  that 
animal,  but  can  in  another,  then  the  natural  conclusion  is  that  the 
uses  are  similar  in  both. 

Though  the  bee  may  be  classed  in  some  degree  among  the 

* [If  the  objects  of  the  comparative  anatomist  were  limited  to  the  elucidation 
of  the  function  of  the  organs  he  dissected,  there  might  then,  perhaps,  be  some 
reason  in  the  animadversions  in  the  text;  but  his  researches  have  a still  higher 
aim,  viz.,  to  trace  the  general  plan  which  pervades  the  construction  of  animals 
amidst  the  various  modifications  to  which  each  organ  is  subject  in  reference  to 
particular  functions  ; and  the  study  of  organic  homologies  requires  that  attention 
be  paid  to  the  minutest  particulars,  independently  of  considerations  as  to  the  uses 
in  the  ceconomy  to  which  they  may  be  subservient.] 


OBSERVATIONS  ON  BEES. 


417 


domestic  animals,  yet  from  there  being  such  a cluster  of  them,  and 
because  they  are  an  offensive  and  irritable  animal,  their  actions  are 
rendered  very  obscure,  and  can  only  be  observed  by  little  starts ; 
often  we  can  only  see  the  effects,  which  renders  the  knowledge  of 
their  ceconomy  still  imperfect:  they  would  in  many  cases  seem  to 
evade  our  wishes ; they  often  remove  out  of  our  sight  part  of  their 
ceconomy  when  they  can.  Thus  they  often  remove  their  eggs  and 
young.  Many  quadrupeds  do  this,  as  cats,  &c.,  and  I have  reason 
to  believe  that  birds  can  remove  their  eggs,  at  least  I have  reason 
to  suspect  the  sparrow  of  this. 

As  the  bee  is  an  insect,  it  has  most  things  peculiar  to  that  class 
of  animals  : such  as  are  common  are  not  to  be  taken  notice  of  in 
the  history  of  this  insect,  but  only  its  peculiarities  which  distinguish 
it  from  all  others,  and  constitirte  it  to  be  a bee  ; and  as  bees  form 
a large  tribe  of  insects,  it  is  the  more  singular  peculiarities  that  con- 
stitute a distinct  species  of  this  tribe.  As  most  parts  of  the  ceconomy 
of  insects  have  not  been  in  every  respect  understood,  and  although 
now  known  in  some  insects  yet  cannot  be  observed  in  the  bee,  but 
which  accord  with  many  circumstances  attending  this  insect,  there- 
fore such  must  be  brought  into  the  present  history  of  the  bee  to 
render  it  more  complete.  I shall  not  be  minute  in  the  anatomy  of 
this  animal,  as  that  would  be  too  tedious  and  uninteresting.  When 
we  talk  of  the  ceconomy  of  the  colony,  such  as  the  secreting  wax, 
making  combs,  collecting  farina,  honey,  feeding  the  maggots, 
covering  in  the  chrysalis  and  the  honey,  stinging,  &c.,  it  is  the 
labouring  bees  that  are  meant. 

In  pursuing  any  subject  most  things  come  to  light  as  it  w^ere  by 
accident,  that  is,  many  things  arise  out  of  investigation  that  were 
not  at  first  conceived,  and  even  misfortunes  in  experiments  have 
brought  things  to  our  knowledge  that  were  not  and  probably  could 
not  have  been  previously  conceived : on  the  other  hand,  I have 
often  devised  experiments  by  the  fire-side  or  in  my  carriage,  and 
have  also  conceived  the  result;  but  w’hen  I tried  the  experiment 
the  result  was  different,  or  I found  that  the  experiment  could  not  be 
attended  with  all  the  circumstances  that  were  suggested. 

As  bees,  from  their  numbers,  hide  very  much  their  operations,  it 
is  necessary  to  have  such  contrivances  as  will  explore  their 
ceconomy.  Hives  with  glass  lights  in  them  often  show  some  of 
their  operations,  and  when  wholly  of  glass  still  more  ; but  as  they 
form  such  a cluster,  and  begin  their  eomb  in  the  centre,  little  can 
be  seen  till  their  work  becomes  enlarged,  and  by  that  lime  they 
have  produced  a much  larger  quantity  of  bees,  so  as  still  to  obscure 
their  progress.  Very  thin  glass  hives  are  the  best  calculated  for 
exposing  their  operations ; the  distance  from  side  to  side  about 
three  inches  ; of  a height  and  length  sufficient  for  a swarm  of  bees 
to  complete  one  summer’s  work  in.  As  one  perpendicular  comb, 
the  whole  length  and  height  of  the  hive,  in  the  centre,  dividing  it 
into  two,  is  the  best  position  for  exposing  their  operations;  it  is 
necessary  to  give  them  a lead  or  direction  to  form  it  so ; therefore 


418 


HUNTER  ON  THE  ANIMAL  (ECONOMY, 


it  is  proper  to  make  a ridge  along  the  top  from  end  to  end,  in  the 
centre,  between  the  two  sides,  for  they  like  to  begin  their  comb 
from  an  eminence ; if  we  wished  to  have  them  transverse  or 
oblique,  it  would  only  be  necessary  to  make  transverse  or  oblique 
ridges  in  the  hive.  I had  one  made  of  two  broad  pieces  of  plate- 
glass,  with  glass  ends,  which  answered  for  simple  exposure  very 
well;  but  I often  saw  operations  going  on  when  I wished  to  have 
caught  some  of  the  bees,  or  to  take  out  a piece  of  comb,  &c. ; 
therefore  I had  hives  made  of  the  same  shape  and  size,  but  with 
difl’erent  panes  of  glass,  each  pane  opening  with  hinges,  so  that  if  I 
saw  anything  going  on  that  I wished  to  examine  more  minutely  or 
immediately,  1 opened  the  pane  at  this  part  and  executed  what  I 
wished  as  much  as  was  in  my  power;  this  I was  obliged  to  do  with 
great  caution,  as  often  the  comb  was  fastened  to  the  glass  at  this 
part.  When  I saw  some  operations  going  on,  the  dates  or  periods 
of  which  I wished  to  ascertain,  such  as  the  time  of  laying  eggs,  of 
liatching,  &c.,  I made  a little  dot  with  white  paint  opposite  to  the 
cell  where  the  egg  was  laid  and  put  down  the  date. 

From  these  animals  forming  colonies,  and  from  a vast  variety 
of  eflects  being  produced,  and  with  a degree  of  attention  and  nicety 
that  seem  even  to  vie  with  man,  man,  not  being  in  the  least  jealous, 
has  wished  to  bestow  on  them  more  than  they  possess,  viz.,  a rea- 
soning faculty;  while  every  action  is  only  instinctive,  and  what 
they  cannot  avoid  or  alter  except  from  necessity,  not  from  fancy. 
They  have  been  supposed  to  be  legislators,  even  mathematicians; 
indeed,  upon  a superficial  view  there  is  some  show  of  reason  for 
such  suppositions;  but  people  have  gone  much  further,  and  have 
filled  up  from  their  imagination  every  blank,  but  in  so  unnatural  a 
way  that  one  reads  it  as  if  it  were  the  description  of  a monster. 
Probably  the  best  way  of  treating  the  history  of  this  insect  is  only 
to  describe  what  is,  and  the  reader  will  immediately  see  where 
authors  have  been  inventing  ; how'ever,  there  are  some  assertions 
that  should  be  particularly  taken  notice  of,  such  as  forming  queen 
bees  at  pleasure. 

Countries  that  have  but  little  variety  in  their  seasons  may  have 
insects  whose  occonomy  is  well  adapted  to  this  uniformity,  and 
which  would  not  be  suited  to  a climate  whose  seasons  are  very  dif- 
ferent ; for  insects  of  countries,  whose  seasons  are  strongly  marked, 
as  in  this,  have  a period  in  their  life  which  it  is  little  in  our  power 
to  investigate,  and  can  scarcely  be  discovered  but  by  accident,  for 
experiments  often  give  little  assistance;  therefore  we  are  obliged  to 
fill  up  this  blank  by  reasoning,  and  from  analogy,  where  we  have 
any.  This  period  is  principally  the  winter,  in  those  insects  which 
live  through  that  season.  Animals  of  season  are  somewhat  like 
most  vegetables,  while  the  common  bee  is  only  an  animal  of  sea- 
sons in  the  common  actions  of  life,  or  what  may  be  called  its  volun- 
tary actions,  and  therefore  it  is  somewhat  like  the  human  species, 
suited  to  every  country,  which  may  be  the  reason  why  it  is  so  uni- 
versally an  animal,  fori  believe  bees  are  one  of  the  most  universal 


OBSERVATIONS  ON  BEES. 


119 


animals  known  yet  this  may  arise  from  cultivation,  in  consequence 
of  which  they  have  been  brought  into  climates  where  of  themselves 
they  would  not  have  come.f 

Insects  are  so  small  and  so  few'^  of  them  are  capable  of  being 
domesticated,  that  the  duration  of  their  life  is  not  easily  ascertained  ; 
therefore  we  are  to  rel3^  more  on  circumstantial  than  on  positive 
or  demonstrative  proof,  and  perhaps  the  life  of  the  common  bee  may 
be  least  in  our  power  to  know,  for  their  numbers  in  the  same  so- 
ciety make  it  almost  impossible  to  be  ascertained.  From  their  form- 
ing a colony  or  society,  which  keeps  stationaiy,  the  continuance 
of  this  society  is  known,  but  to  what  age  the  individual  lives  is  not 
known  ; we  are  certain,  however,  that  it  is  only  the  labourers  and 
queens  that  continue  the  society,  for  the  males  die  the  same  year 
they  are  formed.  From  their  fixing  on  the  branches  of  trees,  under 
projecting  exposed  surfaces,  when  they  swarm,  we  should  be  in- 
clined to  suppose  that  they  were  animals  of  a warm  climate  ; yet 
their  providing  liberally  for  the  change  of  climate,  or  rather  for  a 
change  of  season,  would,  on  the  contrary,  make  us  believe  they 
were  adapted  for  changeable  climates,  or  I’ather  these  two  circum- 
stances should  make  us  suppose  they  were  fitted  for  both,  and  their 
universality  proves  it.  And  I do  conceive  that  in  a pretty  uniform 
warm  climate  their  osconomy  may  be  somewhat  different  from  what 
it  is  in  the  changeable,  as  they  would  not  be  under  the  same  neces- 
sity to  lay  up  so  much  store,  and  probably  might  employ  their  cells 
in  breeding,  for  a much  longer  period  ; however,  a good  climate 
agrees  with  them  best,  as  also  a good  season  in  an  indifferent  cli- 
mate, such  as  Britain.  We  find  the  common  bee  in  Europe,  Asia, 
Africa,  and  America.  That  they  may  be,  or  should  be,  in  the 
three  first  is  easily  supposed,  but  how  they  came  to  America  is  not 
so  readily  conceived ; for  although  a kind  of  manageable  animal, 
yet  they  do  not  like  such  long  confinement  in  their  hives  as  would 
carry  them  to  the  West  Indies,  excepting  in  an  ice-house  ; for  when 
I have  endeavoured  to  confine  them  in  their  hives  they  have  been 
so  restless  as  to  destroy  themselves. 

The  female  and  the  w'orking  bee,  I believe  in  every  species,  have 
stings,  which  renders  them  an  animal  of  offence,  indeed,  but  rather 
of  defence;  for  although  they  make  an  attack,!  believe  it  is  by  way 
of  defence,  excepting  when  they  attack  one  another,  wdiich  is  sel- 
dom or  never  with  their  stings.  As  this  belongs  more  to  the  labour- 
ers, it  shall  be  considered  when  I treat  of  them  in  particular.  Of 
the  whole  bee  tribe,  the  common  bee  is  the  easiest  irritated  ; for  as 

* [The  humble  bee  was  found  by  Captain  Parry  in  Melville  Island,  Arctic 
circle.] 

f [Tbe  true  honeybee  {Apis  mellijica)  was  originally  limited  in  its  geographical 
range  to  the  old  world,  whence  it  has  been  transported  to  America  and  othercolo- 
nies,  where  it  is  now  acclimated.  The  distinguished  entomologist  Latreille,on 
whose  authority  we  state  this  fact,  finds  that  the  hive  bee  of  the  south  and  east 
of  Europe  and  that  of  Egypt  differ  specifically  from  the  Apis  mcUifica  of  the  west 
of  Europe.] 


420 


HUNTER  ON  THE  ANIMAL  CEUONOMY. 


they  have  properly,  they  are  jealous  of  it,  and  seem  to  defend  it ; 
but  when  not  near  it  they  are  quiet,  and  must  be  hurt  before  they 
will  sting ; with  all  this  disposition  for  defence,  which  is  only  to  se- 
cure their  property  or  themselves,  when  more  closely  attacked,  yet 
they  have  no  covetousness,  nor  a disposition  to  obstruct  others. 
Thus  two  bees  or  more  will  be  sucking  at  the  same  flower,  with- 
out the  first  possessor  claiming  it  as  his  right;  a hundred  may  be 
about  the  same  drop  of  honey,  if  it  is  beyond  the  boundaries  of  their 
ow’n  right ; but  what  they  have  collected  they  defend.  It  is  easily 
known  when  they  mean  to  sting  ; they  fly  about  the  object  of  their 
anger  very  quickly,  and  by  the  quickness  of  their  motion  evade 
being  struck  or  attacked;  which  is  discovered  by  the  sound  of 
their  wings,  as  if  going  to  give  a stroke  as  they  fly,  a very  different 
noise  from  that  of  the  wings  when  coming  home  of  a fine  evening 
loaded  with  farina  or  honey  ; it  is  then  a soft,  contented  noise. 
When  a single  bee  is  attacked  by  several  others,  it  seems  the  most 
passive  animal  possible,  making  no  resistance,  and  even  hardly 
seeming  to  wish  to  get  away  ; and  in  this  manner  they  allow  them- 
selves to  be  killed.  They  are  perhaps  the  only  insect  that  feeds  in 
the  winter,  and  therefore  the  only  one  that  lays  up  external  store  ; 
and  as  all  animals,  whether  insects  or  not,  that  keep  quiet  in  the 
winter,  without  either  eating  at  all,  or  eating  very  little  in  propor- 
tion to  what  they  do  in  the  summer,  grow  fat  and  muscular  in  the 
summer  (which  I term  internal  store),  we  see  why  the  common  bee 
need  not  be  fatter  at  one  time  than  another ; and  accordinjily  W'e 
find  them  nearly  of  the  same  fatness  the  yc^af  round. 

There  are  accidents  befalling  hives  of  bees  that  are  not  easily  ac-  . 
counted  for.  I had  a hive,  which  in  the  month  of  November  w'as 
become  quite  empty  of  bees,  and  upon  examination  had  no  honey 
in  it,  which  was  strong  in  the  summer,  and  had  violent  attacks 
made  upon  it  in  October  by  wasps  belonging  to  a nest  in  the  gar- 
den, but  appeared  quiet  when  that  nest  was  removed.  Upon 
examining  this  hive,  I found  only  five  dead  bees,  and  not  a drop  of 
honey  in  any  one  cell  : there  was  a good  deal  of  bee  bread  in  dif- 
ferent cells  scattered  up  and  down  the  comb,  which  was  become 
white  with  mould  on  its  surface.  On  the  other  hand,  I have  had 
sw'arms  die  in  the  winter  in  the  hives,  while  there  was  great  plenty 
of  honey  in  the  combs  ; what  seemed  remarkable,  they  all  died  with 
their  proboscides  elongated,  and  in  those  which  I opened,  I found 
the  stomachs  full  of  honey,  and  their  intestines  full  also  of  excre- 
ment, especially  the  last  part. 

Of  the  Heat  of  Bees. 

Bees  are  perhaps  the  only  insects  that  produces  heat  within  itself,'*' 

* [It  has  been  long  known  that  other  social  insects  besides  the  bee  maintain, 
when  congregated  in  their  habitations,  a higher  temperature  than  that  of  the 
external  atmosphere.  In  an  excellent  and  highly  important  series  of  experi- 
ments on  this  subject  recently  communicated  by  Mr.  Newport  to  the  Royal 
Society,  it  is  shown  that  insects  in  general  have  the  power  of  generating  animal 


OBSERVATIONS  ON  BEES. 


421 


and  were  therefore  intended  to  have  a tolerably  well-regulated 
warmth,  without  which,  of  course,  they  are  very  uncomfortable 
and  soon  die  ; and  which  makes  not  only  a part  of  their  internal 
CBConomy  respecting  the  individual,  but  a part  of  their  external  or 
common  oeconomy,  and  is  therefore  necessary  to  be  known.  The 
heat  of  bees  is  ascertainable  by  the  thermometer,  and  I shall  give 
you  the  result  of  experiments  made  at  two  different  seasons  of  the 
year. 

July  18th,  at  ten  in  the  evening,  wind  northerly,  thermometer  at 
54°  in  the  open  air,  I introduced  it  into  the  top  of  a hive  full  of  bees, 
and  in  less  than  five  minutes  it  rose  to  82°.  I let  it  stand  all  night ; 
at  five  in  the  morning  it  was  down  at  79°;  at  nine  in  the  same 
morning  it  had  risen  to  83°,  and  at  one  o’clock  to  84°;  and  at  nine 
in  the  evening  it  was  down  to  78°. 

December  30th,  air  at  35°,  bees  at  73°. 

Although  bees  support  a heat  nearly  equal  to  that  of  a quadruped, 
yet  their  external  covering  is  not  difierent  from  that  of  insects  which 
do  not;  there  is  no  difference  between  their  coat  and  common  fly’s 
or  wasp’s,  nor  are  they  fatter,  all  which  makes  them  bad  retainers 
of  heat ; therefore  they  are  chilly,  and  in  a cold  too  severe  for  them 
to  be  comfortable  in,  they  make  up  for  their  w'ant  of  size  singly  and 
get  into  clusters.  A single  bee  has  so  little  power  of  keeping  itself 
warm,  that  it  presently  becomes  numbed,  and  almost  motionless:  a 
common  night  in  summer  will  produce  this  effect.  A cold  capable 
of  producing  such  effects  kills  them  soon,  by  w'hich  means  vast  num- 
bers die  ; therefore  a common  bee  is  obliged  to  feed  and  live  in 
society  to  keep  itself  warm  in  cold  weather. 

We  know  that  the  consumption  of  heat  may  be  greater  than  the 
pow’er  of  forming  it;  when  that  is  the  case  we  become  sensible  of 
it,  and  then  take  on  such  actions  as  are  either  instinctive,  such  as  arise 
naturally  out  of  the  impression,  or  as  reason,  custom,  or  habit  di- 
rect. Many  animals  upon  the  impression  of  cold,  coil  themselves 
up  in  their  own  fur,  bringing  all  their  extremities  into  the  centre  or 
hollow  of  the  belly  ; birds  bring  their  feet  under  the  belly,  and 
thrust  their  bill  between  their  wing  and  body;  many  if  not  all,  go 
to  the  warmest  places,  either  from  instinctive  principle  or  habit ; 
but  the  bees  have  no  other  mode  but  forming  clusters,  and  the  larger 

heat ; that  that  power  in  the  solitary  insects  is  greatest  in  the  diurnal  species  of 
flying  insects,  especially  such  as  reside  most  constantly  in  the  open  air.  The 
law  that  the  mature  or  more  perfect  animal  is  “ more  capable  of  generating  heat 
than  when  it  is  younger”  (see  p.  159),  is  well  exemplified  by  Mr.  Newport  in 
the  class  of  insects. 

In  the  Lepidoptera,  the  average  elevation  of  the  temperature  of  the  body  above 
that  of  its'  surrounding  medium  is  in  the  larvae  from  0°.9,  to  1°.5,  while  in 
the  imago  it  is  from  5°  to  10°.  Among  the  Hyinenoptera  it  is  from  2°  to  4°  in 
the  larva,  and  in  the  imago  from  4°  to  15°,  or  even  20°.  In  all  these  cases  the 
amount  of  animal  heat  developed  is  in  the  ratio  of  the  consumption  of  oxygen 
and  the  quantity  of  carbonic  acid  formed  in  the  change  of  the  arterial  into  serous 
blood  ; or  in  other  words,  in  proportion  to  the  energy  with  which  the  functions 
of  respiration  and  locomotion  go  on  in  the  insect.] 

37 


422 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


the  better.  As  they  are  easily  affected  by  cold,  their  instinctive 
])rinciple  respecting  cold  is  very  strong,  as  likewise  with  regard  to 
wet.  I have  seen  a swarm  hanging  out  at  the  door  of  a hive  ready 
to  take  flight,  and  then  return ; a chill  has  come  on  of  which  I M'as 
not  sensible,  and  in  a few  minutes  the  whole  has  gone  back  into  the 
hive  ; and  by  the  cold  increasing,  I have  at  length  perceived  the 
cause  of  their  return.  If  rain  is  coming  on,  we  observe  them  re- 
turning home  in  great  quantities,  and  hardly  any  abroad.  The 
eggs  of  bees  require  this  heat  as  much  as  themselves,  nor  will  the 
maggot  live  in  a cold  of  60°  or  70°,  nor  even  their  chrysalis.  This 
warmth  keeps  the  wax  so  soft  as  to  allow  them  to  model  it  with 
ease.  In  glass  hives,  or  those  that  have  windows  of  glass  in  them, 
we  often  find  a dew  on  the  inside  of  the  glass,  especially  when  the 
glass  is  colder  than  the  air  within  ; whether  this  is  perspiration 
from  the  bees,  both  from  their  external  surface  and  lungs,  or  eva- 
poration from  the  honey,  I cannot  say. 

Bees  are  very  cleanly  animals  respecting  themselves,  although 
not  so  respecting  the  remains  of  their  young.  They,  I believe, 
seldom  or  never  evacuate  their  excrement  in  the  hive.  I have 
known  them  confined  many  days  without  discharging  the  contents 
of  the  rectum,  and  the  moment  they  got  abroad  they  evacuated  in 
the  air  when  flying;  and  they  appear  to  be  very  nice  in  their  bodies, 
for  I have  often  detected  them  cleaning  one  another,  more  especially 
if  by  accident  they  are  besmeared  with  honey. 

This  animal  may  be  considered  alone,  or  so  far  as  concerns  its 
own  oeconomy  as  an  individual,  which  is  common  to  the  most 
solitary  animals;  but  it  can  also  be  considered  as  a member  of 
society,  in  w'hich  it  is  taking  an  active  part,  and  in  which  it  becomes 
an  object  of  great  curiosity. 

To  consider  this  society  individually,  it  may  be  said  to  consist  of 
a female  breeder,  female  non-breeders,  and  males ; but  to  consider 
it  as  a community,  it  may  be  said  to  consist  only  of  female  breeders 
and  non-breeders,  the  males  answ'ering  no  other  purpose  than 
simply  as  a male,  and  are  only  temporary;  and  it  is  probable  the 
female  breeder  is  to  be  considered  in  no  other  light  than  as  a layer 
of  eggs,  and  that  she  only  influences  the  non-breeders  by  her  pre- 
sence, being  only  a bond  of  union,  for  without  her  they  seem  to 
have  no  tie  ; it  is  her  presence  that  makes  them  an  aggregate 
animal.  May  we  not  suppose  that  the  oflspring  of  the  queen  have 
an  attachment  to  the  mother,  somewhat  similar  to  the  attachment 
of  young  birds  to  the  female  that  brings  them  up  ? for  although  the 
times  of  their  attachment  are  not  equal,  yet  it  is  the  dependence 
which  each  has  on  its  motlier  that  constitutes  the  bond  ; for  bees 
have  none  without  her:  however,  the  similarity  is  not  exact,  for 
young  animals  who  have  lost  their  nurse  will  herd  together,  and 
jointly  make  the  best  shifts  they  can,  because  in  future  they  are  to 
become  single  animals ; but  bees  have  an  eternal  instinctive  depend- 
ence on  the  mother,  probably  from  there  not  being  distinct  sexes. 
When  the  queen  is  lost,  this  attachment  is  broke;  they  give  up  in- 


OBSERVATIONS  ON  BEES. 


423 


dustry,  probably  die,  or  we  may  suppose,  join  some  other  hive. 
This  is  not  the  case  with  those  of  this  tribe  whose  queen  singly 
forms  a colony;  for  although  the  queen  is  destroyed,  yet  they  go  on 
with  that  work  which  is  their  lot,  as  the  wasp,  hornet,  and  humble 
bee.  Most  probably  the  whole  ceconomy  of  the  bee,  which  we  so 
much  admire,  belongs  to  the  non-breeders,  and  depends  on  their 
instinctive  powers  being  set  to  wmrk  by  the  presence  of  the  breeders, 
that  being  their  only  enjoyment ; therefore  when  we  talk  of  the 
wonderful  ceconomy  of  bees,  it  is  chiefly  the  labourers  at  large  w-e 
are  to  admii'e,  although  the  queen  gets  the  principal  credit  for  the 
extent  of  their  instinctive  properties. 

This  ceconomy,  in  its  appearances  and  operations,  is  somewhat 
similar  to  human  society,  but  very  different  in  its  first  causes  and 
mode  of  conduct.  The  human  species  sets  up  its  own  standard  ; 
the  bee  has  one  set  up  by  nature,  and  therefore  fulfils  all  the  neces- 
sary purposes.  This  standard  of  influence,  w'hichis  the  breeder,  is 
called  the  queen,  and  I shall  keep  to  the  name,  although  I do  not 
allow  her  voluntary  influence  or  pow’er. 

The  non-breeders  are  what  compose  the  hive,  or  what  may  be 
called  the  community  at  large ; and  the  males  are  mere  males : 
each  of  these  parts  of  the  community  I shall  hereafter  consider 
separately. 

To  take  up  the  common  bee  in  any  one  period  of  the  year,  or  in 
other  words,  in  any  one  month,  and  carry  it  round  lo  the  same,  and 
observe  what  happens  in  that  time,  is  probably  including  the  whole 
ceconomy  of  bees ; for  although  they  may  live  more  than  one  year, 
which  I believe  is  not  known,  from  its  not  being  easily  ascertained, 
yet  each  year  can  only  be  a repetition  of  the  last,  as  I conceive  they 
are  complete  in  the  first;  therefore  the  history  of  one  year  may  be 
said  to  make  a whole,  and  of  course  it  is  not  material  at  what  time 
in  the  circle  we  begin  the  history. 

Perhaps  the  best  time  to  begin  the  history  of  such  insects  as 
only  come  to  full  growth  the  season  they  are  bred,  and  live  through 
the  winter,  and  breed  the  summer  following,  is  w'hen  they  emerge 
from  the  torpid  state,  and  begin  to  breed  ; but  it  might  be  thought 
that  the  common  bee  is  an  exception  to  this  rule,  because  they  begin 
early  in  the  spring  to  breed,  generally  before  they  can  be  observed  ; 
and  as  they  breed  to  form  a colony,  which  is  to  go  off  from  the  old 
stock,  in  order  to  set  out  anew,  it  might  seem  most  natural  to  begin 
with  this  colony,  and  trace  it  through  its  various  actions  of  life  for 
one  year,  when  it  as  it  were  regenerates  itself,  and  comes  round  to 
the  same  point  again  that  the  old  stock  w'as  in  when  it  threw  off 
this  colony. 

Bees,  like  every  other  animal  that  is  taken  care  of  in  the  time  of 
breeding  or  incubation,  and  nursed  to  the  age  of  taking  care  of 
itself,  cannot  be  said  to  have  a period  in  w'hich  we  can  begin  its 
natural  history;  but  in  some  other  insects  there  is  such  a period, 
for  they  can  be  traced  from  an  egg,  becoming  totally  independent 
of  the  parent  from  the  moment  of  being  laid,  as  the  silk-worm,  &c. 


424 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


There  are  three  periods  at  which  the  history  of  the  bee  may  com- 
mence: first,  in  the  spring,  when  the  queen  begins  to  lay  her  eggs; 
in  the  summer,  at  the  commencement  of  a new  colony;  or  in  the 
autumn,  when  they  are  going  into  winter-quarters.  I shall  begin 
the  particular  history  of  the  bee  with  the  new  colony,  when  nothing 
is  formed  ; for  it  then  begins  everything  that  can  possibly  happen 
afterwards. 

When  a hive  sends  off  a colony  it  is  commonly  in  the  month  of 
.June;  but  that  will  vary  according  to  the  season,  for  in  a mild 
spring  bees  sometimes  swarm  in  the  middle  of  May,  and  very  often 
at  the  latter  end  of  it.  Before  they  come  off  they  commonly  hang 
about  the  mouth  of  tlie  hole  or  door  of  the  hive  for  some  days,  as 
if  they  had  not  sufficient  room  within  for  such  hot  weather,  which 
1 believe  is  very  much  the  case  ; for  if  cold  or  wet  weather  come 
on,  they  stow  themselves  very  well,  and  w'ait  for  fine  weather. 
But  swarming  appears  to  be  rather  an  operation  arising  from 
necessity,  for  they  would  seem  not  naturally  to  swarm,  because  if 
they  have  an  empty  space  to  fill,  they  do  not  swarm  ; therefore  by 
increasing  the  size  of  the  hive,  the  swarming  is  prevented.  This 
period  is  much  longer  in  some  than  in  others.  For  some  evenings 
before  they  come  off,  is  often  heard  a singular  noise,  a kind  of  ring,  or 
sound  of  a small  trumpet ; by  comparing  it  with  the  notes  of  the  piano- 
forte, it  seemed  to  l)e  the  same  sound  with  the  lower  A of  the  treble. 

The  swarm  commonly  consists  of  three  classes ; a female,  or 
females,^  males,  and  those  commonly  called  mules,  which  are  sup- 
posed to  be  of  no  sex,  and  are  the  labourers;  the  whole  about  two 
quarts  in  bulk,  making  about  six  or  seven  thousand.  It  is  a question 
that  cannot  easily  be  determined,  whether  this  old  stock  sends  off 
entirely  young  of  the  same  season,  and  whether  the  whole  of  their 
young  ones,  or  only  part.  As  the  males  are  entirely  bred  in  the 
same  season,  part  go  off;  but  part  must  stay,  and  most  probably 
it  is  so  with  the  others.  They  commonly  come  off  in  the  heat  of 
the  day,  often  immediately  after  a shower;  who  takes  the  lead  I do 
not  know,  but  should  suppose  it  was  the  queen.  When  one  goes 
off  they  all  immediately  follow,  and  fly  about  seemingly  in  great 
confusion,  although  there  is  one  principle  actuating  the  whole. 
They  soon  appear  to  be  directed  to  some  fixed  place,  such  as  the 
branch  of  a tree  or  bush,  the  cavities  of  old  trees,  holes  of  houses 
leading  into  some  hollow  place  ; and  whenever  the  stand  is  made, 
they  all  immediately  repair  to  it,  till  they  are  all  collected.  But  it 
would  seem  in  some  cases  that  they  had  not  fixed  upon  any  resting 
place  before  they  came  off,  or  if  they  had,  that  they  were  either 
disturbed,  if  it  was  near,  or  that  it  was  at  a great  distance ; for  after 
hovering  some  time,  as  if  undetermined,  they  fly  away,  mount  up 
into  the  air,  and  go  off  with  great  velocity.  When  they  have  fixed 
upon  their  future  habitation,  they  immediately  begin  to  make  their 
combs,  for  they  have  the  materials  within  themselves.  I have 

* I have  reason  to  believe  that  never  more  than  one  female  comes  off  with  a 
swarm. 


OBSERVATIONS  ON  BEES. 


425 


reason  to  believe  that  they  fill  their  crops  with  honey  when  they 
come  away;  probably  from  the  stock  in  the  hive.  I killed  several 
of  those  that  came  away,  and  found  their  crops  full,  while 
those  that  remained  in  the  hive  had  their  crops  not  near  so  full : 
some  of  them  came  away  with  farina  on  their  legs,  which  I con- 
ceive to  be  rather  accidental.  I may  just  observe  here,  tliat  a hive 
commonly  sends  off  two,  sometimes  three  swarms  in  a summer  ; 
but  that  the  second  is  commonly  less  than  the  first,  and  the  third 
less  than  the  second  ; and  this  last  has  seldom  time  to  provide  for 
the  wititer  : they  shall  often  threaten  to  swarm,  but  do  not ; whether 
the  threatening  is  owing  to  too  many  bees,  and  their  not  swarming 
is  owing  to  there  being  no  queen,  I do  not  know.  It  sometimes 
happens  that  the  swarm  shall  go  back  again ; but  in  such  instances 
I have  reason  to  think  that  they  have  lost  their  queen,  for  the  hives 
to  which  their  swarm  have  come  back  do  not  swarm  the  next  warm 
day,  but  shall  hang  out  for  a fortnight  or  more,  and  then  swarm  ; 
and  when  they  do,  the  swarm  is  commonly  much  larger  than  be- 
fore, which  makes  me  suspect  that  they  waited  for  the  queen  that 
was  to  have  gone  off  with  the  next  swarm. 

So  far  we  have  set  the  colony  in  motion.  The  materials  of  their 
dwelling,  or  comb,  which  is  the  wax,  is  the  next  consideration,  with 
the  mode  of  forming,  preparing,  or  disposing  of  it.  In  giving  a to- 
tally new  account  of  the  wax,  I shall  first  show  it  can  hardly  be 
what  it  has  been  supposed  to  be.  First  I shall  observe  that  the 
materials,  as  they  are  found  composing  the  comb,  are  not  to  be 
found  in  the  same  state  (as  a composition)  in  any  vegetable,  where 
they  have  been  supposed  to  be  got.  The  substance  brought  in  on 
their  legs,  which  is  the  farina  of  the  flowers  of  plants,  is,  in  common, 
I believe,  imagined  to  be  the  materials  of  which  the  wax  is  made, 
for  it  is  called  by  most  the  wax  : but  it  is  the  farina,  for  it  is  always 
of  the  same  colour  as  the  farina  of  the  flower  where  they  are  gather- 
ing; and  indeed  we  see  them  gathering  it,  and  we  also  see  them 
covered  almost  all  over  wdth  it,  like  a dust;  nevertheless,  it  has 
been  supposed  to  be  the  wax,  or  that  the  wax  was  extracted  from 
it.  Reaumur  is  of  this  opinion.  I made  several  experiments  to  see 
if  there  was  such  a quantity  of  oil  in  it  as  would  account  for  the 
quantity  of  wax  to  be  formed,  and  to  learn  if  it  was  composed  of 
oil.  I held  it  near  the  candle ; it  burnt,  but  did  not  smell  like  wax, 
and  had  the  same  smell  when  burning,  as  farina  when  it  was  burnt. 
I observed  that  this  substance  was  of  different  colours  on  different 
bees,  but  always  of  the  same  colour  on  both  legs  of  the  same  bee;^ 

* [Aristotle,  who  describes  many  interesting-  particulars  of  the  oeconomy  of 
the  bee,  and  knew  something  of  the  structure  of  the  interior  of  the  hive,  was  the 
first  to  observe  that  a bee  in  each  single  excursion  from  the  hive  always  visits 
the  same  species  of  flower,  and  consequently  comes  home  laden  with  pollen  of 
the  same  colour.  This  has  been  confirmed  by  all  subsequent  observers,  and,  as 
we  see,  did  not  escape  Mr.  Hunter.  The  necessity  for  this  instinct  arises  out 
of  the  operation  which  the  pollen  first  undergoes  ; the  bee  rakes  out  the  pollen 
with  incredible  quickness  by  means  of  its  first  pair  of  legs,  then  passes  it  to  the 
middle  pair,  which  transfer  it  to  the  hind  legs,  by  which  it  is  wrouo-ht  up  into 

37*^ 


426 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


whereas  new-made  comb  was  all  of  one  colour.  I observed  that 
it  was  gathered  with  more  avidity  for  old  hives,  where  the  comb 
is  complete,  than  for  those  hives  where  it  is  only  begun,  which  we 
f’ould  hardly  conceive  if  it  was  the  materials  of  wax  : also  we  may 
observe  that  at  the  very  beginning  of  a hive,  the  bees  seldom  bring 
in  any  substance  on  their  legs  for  two  or  three  days,  and  after  that 
the  farina  gatherers  begin  to  increase ; for  now  some  cells  are 
formed  to  hold  it  as  a store,  and  some  eggs  are  laid,  which  when 
hatched  will  require  this  substance  as  food,  and  which  will  be  ready 
when  the  weather  is  wet.  I have  also  observed,  that  when  the 
weather  has  either  been  so  cold,  or  so  wet,  in  June,  as  to  hinder  a 
young  swarm  from  going  abroad,  they  have  yet  in  that  time  formed 
as  much  new  comb  as  they  did  in  the  same  time  when  the  weather 
was  such  as  allowed  them  to  go  abroad.  I have  seen  them  bring 
it  in  about  the  latter  end  of  March,  and  have  observed  in  glass 
hives  the  bees  with  the  farina  on  their  legs,  and  have  seen  them  dis- 
posing of  it,  as  will  be  described  hereafter. 

The  wax  is  formed  by  the  bees  themselves  ; it  may  be  called  an 
external  secretion  of  oil,  and  I have  found  that  it  is  formed  be- 
tween each  scale  of  the  under  side  of  the  belly.*  When  I first  ob- 
served this  substance,  in  my  examination  of  the  working  bee,  I w’as 
at  a loss  to  say  what  it  was : I asked  myself  if  it  was  new  scales 
forming,  and  whether  they  cast  the  old,  as  the  lobster,  &c.,  does? 
But  it  was  to  be  found  only  between  the  scales,  on  the  lower  side 
of  the  belly.  On  examining  the  bees  through  glass  hives  while  they 
were  climbing  up  the  glass  I could  see  that  most  of  them  had  this 
substance,  for  it  looked  as  if  the  lower  or  posterior  edge  of  the 
scale  was  double,  or  that  there  were  double  scales;  but  I perceived 
it  was  loose,  not  attached.  Finding  that  the  substance  brought  in 
on  their  legs  was  farina,  intended,  as  appeared  from  every  circum- 
stance, to  be  the  food  of  the  maggot,  and  not  to  make  wax,  and  not 
having  yet  perceived  anything  that  could  give  me  the  least  idea 
of  wax,  I conceived  these  scales  might  be  it,  at  least  I thought  it 
necessary  to  investigate  them.  I therefore  took  several  on  the 
point  of  a needle,  and  held  them  to  a candle,  where  they  melted, 
and  immediately  formed  themselves  into  a round  globe  ; upon  which 
I no  longer  doubted  but  this  was  the  wax,  which  opinion  was  con- 

little  pellets.  Now  if  the  pollen  were  taken  indiscriminately  from  different 
flowers,  the  difference  in  the  size  and  shape  of  the  pollen-grains  would  probably 
prevent  them  cohering  together  sufficiently  to  allow  of  the  pellet  being  formed. 
Hence  it  is  that  in  watching  the  return  of  bees  to  the  hive  some  may  be  seen 
laden  with  yellow-coloured  pellets,  others  with  orange,  pink,  white,  or  greenish- 
coloured  ones.  The  grains  of  pollen  are  not  changed  by  the  operation  of  kneading 
when  detached  from  the  pellet;  under  a miscroscope  they  are  seen  to  possess 
their  original  figure.] 

* [Hunter  first  confirmed  this  statement  by  actual  observation,  but  the  merit 
of  the  discovery  is  entirely  Hunter’s.  The  only  approach  to  it  is  in  the  observa- 
tion by  Morley,  who  says  that  he  has  taken  bees  with  six  pieces  of  wax  within 
the  plaits  of  the  abdomen,  three  on  each  side  {Female  Monarchy,  1774),  but  with- 
out knowing  the  source  of  these  pieces  of  wax.] 


OBSERVATIONS  ON  BEES. 


427 


firmed  to  me  by  not  finding  those  scales  but  in  the  building  season. 
In  the  bottom  of  the  hive  we  see  a good  many  of  the  scales  lying 
loose,  some  pretty  perfect,  others  in  pieces.  1 have  endeavoured 
to  catch  them,  either  taking  this  matter  out  of  themselves,  from  be- 
tween the  scales  of  the  abdomen,  or  from  one  another,  but  never 
could  satisfy  myself  in  this  respect : however  I once  caught  a bee 
examining  between  the  scales  of  the  belly  of  another,  but  I could 
not  find  that  it  took  anything  from  between.  We  very  often  see 
some  of  the  bees  wagging  their  belly,  as  if  tickled,  running  round 
and  to  and  fro  for  only  a little  way,  followed  by  one  or  two  other 
bees,  as  if  examining  them.  I conceived  they  were  probably  shak- 
ing out  the  scales  of  wax,  and  that  the  others  were  ready  upon 
the  watch  to  catch  them,  but  1 could  not  absolutely  determine  what 
they  did.  It  is  with  these  scales  that  they  form  the  cells  called  the 
comb,  but  perhaps  not  entirely,  for  I believe  they  mix  farina  wdth 
it;  however,  this  only  occasionally,  when  probably  the  secretion  is 
not  in  great  plenty.  I have  somo  reason  to  think  that  where  no 
other  substance  is  introduced  the  thickness  of  the  scale  is  the  same 
with  that  of  the  sides  of  the  comb;  if  so,  then  a comb  may  be  no 
more  than  a number  of  these  united  ; but  a great  deal  of  the  comb 
seems  to  be  too  thick  for  this,  and,  indeed,  would  appear  to  be  a 
mixture  similar  to  the  covering  of  the  chrysalis.  The  w'ax  natu- 
rally is  white,  but  when  melted  from  the  comb  at  large  it  is  yellow. 
I apprehended  this  might  arise  from  its  being  stained  with  honey, 
the  excrement  of  the  maggots,  and  with  the  bee-bread.  I steeped 
some  white  comb  in  honey,  boiled  some  with  farina  as  also  with 
old  comb,  but  I could  not  say  that  it  was  made  yellower.  W ax,  by 
bleaching,  is  brought  back  to  its  natural  colour,  which  is  also  a 
proof  that  its  colour  is  derived  from  some  mixture.  I have  reason 
to  believe  that  they  take  the  old  comb,  when  either  broken  down, 
or  by  any  accident  rendered  useless,  and  employ  it  again  ; but  this 
can  only  be  with  combs,  that  have  had  no  bees  hatched  in  them, 
for  the  wax  cannot  be  separated  from  the  silk  afterwards.  Reau- 
mur supposed  that  they  new  worked  up  the  old  materials,  because 
he  found  the  covering  of  the  chrysalis  of  a yellower  colour  than  the 
other  parts  of  the  new  comb;  but  this  is  always  so,  whether  they 
have  old  yellow  comb  to  work  up  or  not,  as  will  be  shown. 

The  bees  wdio  gather  the  farina  also  form  the  wax,  for  I found  it 
between  their  scales. 

The  cells,  or  rather  the  congeries  of  cells,  which  compose  the 
comb,  may  be  said  to  form  perpendicular  plates  or  partitions,  which 
extend  from  top  to  bottom  of  the  cavity  in  which  they  build  them, 
and  from  side  to  side.  They  always  begin  at  the  top  or  roof  of  the 
vault  in  which  they  build,  and  work  downwards;  but  if  the  upper 
part  of  this  vault,  to  which  their  combs  are  fixed,  is  removed,  and 
a dome  is  put  over,  they  begin  at  the  upper  edge  of  the  old  comb 
and  work  up  into  the  new  cavity  at  the  top.  They  generally  may 
be  guided  as  to  the  direction  of  their  new  plates  of  comb,  by  form- 
ing ridges  at  top,  to  which  they  begin  to  attach  their  comb.  In  a 


428 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


long  hive,  if  these  ridges  are  longitudinal,  their  plates  of  comb  will 
be  longitudinal ; if  placed  transverse,  so  will  be  the  plates  ; and  if 
oblique,  the  plates  of  comb  will  be  oblique.  Each  plate  consists  of 
a double  set  of  cells,  whose  bottoms  form  the  partition  between 
each  set.  The  plates  themselves  are  not  very  regularly  arranged, 
not  forming  a regular  plane  where  they  might  have  done  so;  but 
are  often  adapted  to  the  situation  or  shape  of  the  cavity  in  which 
they  ai'e  built.  The  bees  do  not  endeavour  to  shape  their  cavity  to 
their  work,  as  the  wasps  do,  nor  are  the  cells  of  equal  depths,  also 
fitting  them  to  their  situation  ; but  as  the  breeding  cells  must  all  be 
of  a given  depth,  they  reserve  a sufficient  number  for  breeding  in, 
and  they  put  the  honey  into  the  others,  as  also  into  the  shallow  ones. 
The  attachment  of  the  comb  round  the  cavity  is  not  continued,  but 
interrupted  so  as  to  form  passages  ; there  are  also  passages  in  the 
middle  of  the  plates,  especially  if  there  be  a cross  stick  to  support 
the  comb ; these  allow  of  bees  to  go  across  from  plate  to  plate. 
The  substance  which  they  use  for  attaching  their  combs  to  sur- 
rounding parts  is  not  the  same  as  the  common  wmx  ; it  is  softer  and 
tougher,  a good  deal  like  the  substance  with  which  they  cover  in 
their  chrysalis  or  the  humble  bee  surrounds  her  eggs.  It  is  pro- 
bably a mixture  of  wax  wdth  farina.  The  cells  are  placed  nearly 
horizontally,  but  not  exactly  so ; the  mouth  raised  a little,  which 
probably  may  be  to  retain  the  honey  the  better ; however,  this  rule 
is  not  strictly  observed,  for  often  they  are  horizontal,  and  towards 
the  lower  edge  of  a plane  of  comb  they  are  often  declining.  The 
first  combs  that  a hive  forms  are  the  smallest,  and  much  neater  than 
the  last  or  lowermost.  Their  sides  or  partitions  between  cell  and 
cell  are  much  thinner,  and  the  hexagon  is  much  more  perfect.  The 
wax  is  purer,  being  probably  little  else  but  w'ax,  and  it  is  more 
brittle.  The  lower  combs  are  considerably  larger,  and  contain 
much  more  w’ax,  or  perhaps,  more  properly,  more  materials;  and 
the  cells  are  at  such  distances  as  to  allow  them  to  be  of  a round 
figure  : the  wax  is  softer,  and  there  is  something  mixed  w'ith  it.  I 
have  observed  that  the  cells  are  not  all  of  equal  size,  some  being  a 
degree  larger  than  the  others;  and  that  the  small  are  the  first 
formed,  and  of  course  at  the  upper  part  where  the  bees  begin,  and 
the  larger  are  nearer  the  lower  part  of  the  comb,  or  last  made: 
however,  in  hives  of  particular  construction,  where  the  bees  may 
begin  to  work  at  one  end,  and  can  work  both  down  and  towards 
the  other  end,  w'e  often  find  the  larger  cells  both  on  the  lower  part 
of  the  combs  and  also  at  the  opposite  end. 

These  are  formed  for  the  males  to  be  bred  in;  and  in  the 
hornets’  and  wasps’  combs  there  are  larger  cells  for  the  queens  to 
be  bred  in:  these  are  also  formed  in  the  lower  tier,  and  the  last 
formed. 

The  first  comb  made  in  a hive  is  all  of  one  colour,  viz.,  almost 
white;  but  it  is  not  so  white  towards  the  end  of  the  season,  having 
then  more  of  a yellow  cast. 


OBSERVATIONS  ON  BEES. 


429 


Of  the  Royal  Cell. 

There  is  a cell  which  is  called  the  royal  cell,  often  three  or  four 
of  them,  sometimes  more;  I have  seen  eleven,  and  even  thirteen  in 
the  same  hive;  commonly  they  arc  placed  on  the  edge  of  one  or 
inoi’e  of  the  combs,  biR  often  on  the  side  of  a comb ; however,  not 
in  the  centre  along  with  the  other  cells,  like  a large  one  placed 
among  the  others,  but  often  against  the  mouths  of  the  cells,  and 
projecting  out  beyond  the  common  surface  of  the  comb;  but  most 
of  them  are  formed  from  the  edge  of  the  comb,  which  terminates 
in  one  of  these  cells.  The  royal  cell  is  much  wider  than  the  others, 
but  seldom  so  deep:  its  mouth  is  round,  and  appears  to  be  the 
largest  half  of  an  oval  in  depth,  and  is  declining  downwards,  instead 
of  beincr  horizontal  or  lateral.  The  materials  of  which  it  is  com- 

O 

posed  are  softer  than  common  wax,  rather  like  the  last  mentioned, 
or  those  of  which  the  lower  edge  of  the  plate  of  comb  is  made,  or 
with  which  the  bees  cover  the  chrysalis : they  have  very  little 
wax  in  their  composition,  not  one-third;  the  rest  I conceive  to  be 
farina. 

This  is  supposed  to  be  the  cell  in  which  the  queen  is  bred,  but  I 
have  reason  to  believe  that  this  is  only  imagination:  for,  first,  it  is 
too  large,  and,  moreover,  seldom  so  deep  as  the  large  cells  in  which 
the  males  are  bred;  whereas,  if  proportioned  to  the  length  of  the 
queen,  it  ought  to  be  deeper,  for  length  of  body  is  her  greatest  dif- 
ference. In  the  second  place,  its  mouth  is  placed  downwards  ; and 
in  the  third  place,  it  is  nev'er  lined  with  the  silken  covering  of  the 
chrysalis,  similar  to  the  cells  of  the  males  and  labourers;  nor  do 
we  find  excrement  at  the  bottom  of  it.  The  number  of  these  cells 
is  very  different  in  different  hives.  I think  I have  seen  hives  with- 
out any,  and  I have  seen  them  with  eleven  or  twelve,  sometimes 
more.  I have  examined  them  at  all  times  through  the  summer, 
but  never  found  any  alteration  in  them. 

The  comb  seems  at  first  to  be  formed  for  propagation,  and  the 
reception  of  honey  to  be  only  a secondary  use  ; for  if  the  bees  lose 
their  queen  they  make  no  combs ; and  the  wasp,  hornet,  &c.,  make 
combs,  although  they  collect  no  honey  ; and  the  humble  bee  collects 
honey,  and  deposits  it  in  cells  she  never  made. 

I shall  not  consider  the  bee  as  an  excellent  mathematician,  capa- 
ble of  making  exact  forms,  and  having  reasoned  upon  the  best 
shape  of  the  cell  for  capacity,  so  that  the  greatest  number  might 
be  put  into  the  smallest  space  (for  the  hornet  and  the  wasp  are 
much  more  correct,  although  not  seemingly  under  the  same  neces- 
sity,as  they  collect  nothing  to  occupy  tlieir  cells) ; because,  although 
the  bee  is  pretty  perfect  in  these  respects,  yet  it  is  very  incorrect 
in  others,  in  the  formation  of  the  comb:  nor  shall  I consider  these 
animals  as  forming  comb  of  certain  shape  and  size,  from  mere  me- 
chanical necessity,  as  from  working  round  themselves;  for  such  a 
mould  would  not  form  cells  of  diflerent  sizes,  much  less  could 
wasps  be  guided  by  the  same  principle,  as  their  cells  are  of  very 


430 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


different  sizes,  and  the  first  by  much  too  small  for  the  queen  wasp 
to  have  worked  round  herself:  but  I shall  consider  the  whole  as  an 
instinctive  principle,  in  which  the  animal  has  no  power  of  variation 
or  choice,  but  such  as  arises  from  what  may  be  called  external 
necessity.  I'he  cell  has  in  common  six  sides,  but  this  is  most  cor- 
rect in  those  first  formed  ; and  their  bottom  is  commonly  c,omposed 
of  those  sides  or  planes,  two  of  the  sides  making  one;  and  they 
generally  fall  in  between  the  bottoms  of  three  cells  of  the  opposite 
side  ; but  this  is  not  regular,  it  is  only  to  be  found  where  there  is 
no  external  interruption. 

I have  already  observed,  that  the  last-formed  cells  in  the  season 
are  not  so  well  made  ; that  their  partitions  are  thicker,  and  more 
of  a yellow  colour:  this  arises,  I imagine,  from  the  wax  being  less 
pure,  having  more  alloy  in  it;  and  therefore,  not  being  so  strong, 
more  of  it  is  required.  The  bees  would  appear  to  reserve  many  of 
their  cells  for  honey,  and  those  are  mostly  at  the  upper  part.  In 
old  hives,  of  several  years’  standing,  I have  found  the  upper  part 
of  the  comb  free  from  the  consequences  of  having  bred,  such  as  the 
silk  lining,  and  the  excrement  of  the  maggots  at  the  bottom;  while 
the  lower  part,  for  probably  more  than  one-half  of  the  plane  of 
cells,  showed  strong  marks  of  having  contained  many  broods  of 
young  bees.  In  such  the  lining  of  silk  is  thick  at  the  sides,  com- 
posed of  many  laminte;  and  in  many,  the  bottom  is  half  filled  up 
with  excrement;  and  I observed  at  such  parts,  the  comb  was 
thickest  at  its  mouth,  which  inclines  me  to  think,  that  when  a cell 
becomes  shallow,  by  the  bottom  being  in  some  degree  filled  up,  the 
bees  then  add  to  its  mouth.  Such  also  they  seem  to  reserve  prin- 
cipally for  the  bee-bread ; so  that  to  lay  up  a greater  store  of 
honey  is  an  object  to  them. 

Of  the  Laying  of  Eggs. 

As  soon  as  a few  combs  are  formed,  the  female  bee  begins  laying 
of  eggs.  As  far  as  I have  been  able  to  observe,  the  queen  is  the 
only  bee  that  propagates,  although  it  is  asserted  that  the  labourers 
do.  Her  first  eggs  in  the  season  are  those  which  produce  labourers; 
then  the  males,  and  probably  the  queen;  this  is  the  progress  in  the 
wasp,  hornet,  humble  bee,  &c.  However,  it  is  asserted  by  Riem, 
that  when  a hive  is  deprived  of  a queen,  labourers  lay  eggs  ; also, 
that  at  this  time,  some  honey  and  farina  are  brought  in  as  store  for 
a wet  day.  The  eggs  are  laid  at  the  bottom  of  the  cell,  and  we 
find  them  there  before  the  cells  are  half  completed,  so  that  propa- 
gation begins  early  and  goes  on  along  with  the  formation  of  the 
other  cells.  The  egg  is  attached  at  one  end  to  the  bottom  of  the 
cell,  sometimes  standing  perpendicularly,  often  obliquely;  it  has  a 
glutinous  or  slimy  covering,  which  makes  it  stick  to  anything  it 
touches.  It  would  appear  that  there  was  a period  or  periods  for 
laying  eggs ; for  I have  observed  in  a new  swarm  that  the  great 
business  of  laying  eggs  did  not  last  above  a fortnight ; although  the 


OBSERVATIONS  ON  BEES. 


431 


hive  was  not  half  filled  with  comb,  it  began  to  slacken.  Probably 
that  end  of  the  egg  which  is  first  protruded  is  that  which  sticks  to 
the  bottom  of  the  cell ; and  probably  the  tail  of  the  maggot  is 
formed  at  that  end  : when  they  move  the  egg,  how  they  make  it 
stick  again,  1 do  not  know.  I have  just  observed,  that  they  often 
move  the  egg  out  of  a cell  to  some  other,  we  may  suppose  ; why 
they  do  this  I cannot  say  ; whether  it  is  because  we  have  been 
exposing  this  part,  is  not  easily  determined.  In  those  new-formed 
combs,  as  also  in  many  not  half  finished,  we  find  the  substance 
called  bee-bread,  and  some  of  it  is  covered  over  with  wax,  which 
will  be  considered  further.  By  the  time  they  have  worked  above 
half  way  down  the  hive  with  the  comb,  they  are  beginning  to  form 
the  larger  cells,  and  by  this  time  the  first  broods  are  hatched, 
which  were  small  or  labourers;  and  now  they  begin  to  breed 
males,  and  probably  a queen,  for  a new  swarm  ; because  the  males 
are  now  bred  to  impregnate  the  young  queen  for  the  present  sum- 
mer, as  also  for  the  next  year.  This  progress  in  breeding  is  the 
same  with  that  of  the  wasp,  hornet,  and  humble  bee.*  Although 
this  account  is  commonly  allowed,  yet  writers  on  this  subject  have 
supposed  another  mode  of  producing  a queen,  when  the  hive  is  in 
possession  of  maggots,  and  deprived  of  th*ir  queen. 

What  may  be  called  the  complete  process  of  the  egg,  namely, 
from  the  time  of  laying  to  the  birth  of  the  bee,  (that  is,  the  time  of 
hatching,)  the  life  of  the  maggot,  and  the  life  of  the  chrysalis,  is,  I 
believe,  shorter  than  in  most  insects.  It  is  not  easy  to  fix  the  time 
when  the  eggs  hatch  ; I have  been  led  to  imagine  it  was  in  five  days. 
When  they  hatch,  we  find  the  young  maggot  lying  coiled  up  in  the 
bottom  of  the  cell,  in  some  degree  surrounded  with  a transparent 
fluid.  In  many  of  the  cells,  where  the  eggs  have  just  hatched,  we  find 
the  skin  standing  in  its  place,  either  not  yet  removed,  or  not  pressed 
down  by  the  maggot.  There  is  now  an  additional  employment  for 
the  labourers,  namely,  the  feeding  and  nursing  the  young  maggots. 
We  may  suppose  the  queen  has  nothing  to  do  with  this,  as  there 
are  at  all  times  labourers  enough  in  the  hive  for  such  purposes, 
especially  too  as  she  never  does  bring  the  materials,  as  every  other 
of  the  tribe  is  obliged  to  do  at  first ; therefore  she  seems  to  be  a 
queen  by  hereditary,  or  rather  by  natural  right,  while  the  humble 
bee,  wasp,  hornet,  &c.,  seem  rather  to  work  themselves  into  royalty, 
or  mistresses  of  the  community.  The  bees  are  readily  detected 
feeding  the  young  maggot ; and  indeed  a young  maggot  might  easily 
be  brought  up  by  any  person  who  would  be  attentive  to  feed  it. 
They  open  their  two  lateral  pincers  to  receive  the  food,  and  swallow 
it.  As  they  grow,  they  cast  their  coats  or  cuticles;  but  how  often 


* Reaumur  on  Bees  says  that  the  drone  eggs,  when  laid  in  small  cells, 
produce  drones  ; and  Wilhelmi  says  that  it  is  the  labourers  only  that  lay  drone 
eggs.  Mr.  Riein  says  that  queens  are  never  reared  in  any  but  royal  cells, 
although  males  sometimes  in  common  cells  ; and  workers  in  old  queen  cells,  but 
never  in  those  recently  made. 


432 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


they  throw  their  coats,  while  in  the  maggot  state,  I do  not  know.* 
I observed  that  they  often  removed  their  eggs;  I also  find  they 
very  often  shift  the  maggot  into  another  cell,  even  when  very  large. 
The  maggots  grow  larger  and  larger  till  they  nearly  fill  the  cell ; 
and  by  this  time  they  require  no  more  food,  and  are  ready  to  be 
inclosed  for  the  chrysalis  state:  how  this  period  is  discovered  I do 
not  know,  for  in  every  other  insect,  as  far  as  I am  acquainted,  it  is 
an  operation  of  the  maggot  or  caterpillar  itself ; but  in  the  common 
bee  it  is  an  operation  of  the  perfect  animal ; probably  it  arises  from 
the  maggot  refusing  food.  The  time  between  their  being  hatched 
and  their  being  inclosed  is,  I believe,  four  days  ; at  least,  from  re- 
peated observations,  it  comes  nearly  to  that  time.  When  ready 
for  the  chrysalis  state,  the  bees  cover  over  the  mouth  of  the  cell 
with  a substance  of  a light  brown  colour,  much  in  the  same  man- 
ner that  they  cover  the  honey,  excepting  that  in  the  present  instance 
the  covering  is  convex  externally,  and  appears  not  to  be  entirely 
wax,  but  a mixture  of  wax  and  farina.  The  maggot  is  now  per- 
fectly inclosed,  and  it  begins  to  line  the  cell  and  covering  of  the 
mouth  above-mentioned  with  a silk  it  spins  out  similar  to  the  silk- 
worm, and  which  makes  a kind  of  pod  for  the  chrysalis.  Bonnet 
observed  that  in  one  instance  the  cell  was  too  short  for  the  chrysalis, 
and  it  broke  its  covering,  and  formed  its  pod  higher  or  more  convex 
than  common:  this  I can  conceive  possible;  we  often  see  it  in  the 
wasp.  Having  completed  this  lining,  they  cast  off,  or  rather  shove 
off  from  the  head  backwards,  the  last  maggot  coat,  which  is  de- 
posited at  the  bottom  of  the  cell,  and  then  they  become  chrysalises. 

Of  the  Food  of  the  Maggot,  or  what  is  commonly  called  Bee-Bread. 

One  would  naturally  suppose  that  the  food  of  the  maggot  bee 
should  be  honey,  both  because  it  is  the  food  of  the  old  ones,  and  it 
is  what  they  appear  principally  to  collect  for  themselves  ; however, 
the  circumstance  of  honey  being  food  for  the  old  ones  is  no  argu- 
ment, because  very  few  young  animals  live  on  the  same  food  with 
the  old,  and  therefore  it  is  probable  the  maggot  bee  does  not  live 
upon  honey ; and  if  we  reason  from  analogy,  we  shall  be  led  to 
suppose  the  bee-bread  to  be  the  food  of  the  maggot.  It  is  the  food 
of  the  maggot  of  the  humble  bee,  who  feeds  upon  honey,  and  even 
lays  up  a store  of  honey  fora  w'et  day,  yet  does  not  feed  the  young 
vath  it.  It  is  the  food  of  the  maggot  of  a black  bee,  and  also  of 
several  others  of  the  solitary  kind  who  also  feed  upon  honey  ; and 
wasps,  &c.,  who  do  not  bring  in  such  materials,  do  not  feed  them- 
selves upon  honey.  We  cannot  suppose  that  the  bee-bread  is  for 
the  food  of  the  old  bees,  when  we  see  them  collecting  it  in  the 
months  of  June  and  July,  &c.,  at  which  time  they  have  honey  in 

* [It  has  not  yet  been  ascertained  that  the  larva  of  the  bee  sheds  its  skin,  as 
the  lepidopterous  caterpillars  do,  except  when  on  the  point  of  becoming  a pupa, 
at  which  period  a thin  pellicle  is  also  thrown  out  by  each  of  the  stigmata  from 
the  tracheal  tubes.] 


OBSERVATIONS  ON  BEES. 


433 


great  plenty ; this  substance  is  as  common  to  a hive  as  any  part  be- 
longing to  the  oeconomy  of  bees.  Before  they  have  formed  five  or 
six  square  inches  of  comb  in  a young  hive,  we  shall  find  eggs, 
honey,  and  bee-bread  ; and  at  whatever  time  of  the  year  we  kill  a 
hive,  we  shall  find  this  substance  ; and  if  a hive  is  short  of  honey 
and  dies  in  the  winter,  we  find  no  honey,  but  all  the  bee-bread,  which 
was  laid  up  in  store  for  the  maggots  in  the  spring.  They  take  great 
care  of  it,  for  it  is  often  covered  over  with  wax  as  the  honey,  and  I 
believe  more  especially  in  the  winter  ; probably'  with  a view  to  pre- 
serve it  till  wanted.  In  April  I have  found  some  of  the  cells  full, 
others  only  half  full.  If  we  slit  down  a cell  filled  with  this  sub- 
stance, we  shall  commonly  find  it  composed  of  laymrs  of  different 
colours  ; some  a deep  orange,  others  a pale  brown.  In  glass  hives 
we  often  find  that  the  glass  makes  one  side  of  the  cell,  and  frequently 
in  such  w'e  shall  see  at  once  the  different  strata  above-mentioned^  This 
is  the  substance  which  they  bring  in  on  their  legs,  and  consists  of 
the  farina  of  plants.  It  is  not  the  farina  of  every  plant  that  the 
bee  collects,  at  least  they  are  found  gathering  it  from  some  with 
great  industry,  while  we  never  find  them  on  others:  St.  John’s 
w'ort  is  a favourite  plant,  but  that  comes  late.  The  flower  of  the 
gourd,  cucumber,  &c.,  they  seem  to  be  fond  of.  What  they  do 
collect  must  be  the  very  loose  stuff’,  just  ready'  to  be  blown  off  to  im- 
pregnate the  female  part  of  the  flower  ; and  to  show  that  this  is  the 
case,  w'e  find  bees  impregnate  flowers  that  have  not  the  male  part. 
It  is  in  common  of  a yellow  colour,  but  that  of  difl’erent  shades, 
often  of  an  orange ; and  w'hen  we  see  bees  collecting  it  on  bushes 
that  have  a great  many  flow'ers,  so  as  to  furnish  a complete  load, 
it  is  then  of  the  colour  of  the  farina  of  that  bush.  It  is  curious  to 
see  them  deposite  this  substance  in  the  cell.  On  viewing  the  hives, 
W'e  often  see  bees  with  this  substance  on  their  legs,  moving  along 
on  the  combs,  as  if  looking  out  for  the  cell  to  deposit  it  in.  They 
will  often  walk  over  a cell  that  has  some  deposited  in  it,  but  shall 
leav'e  that,  and  try  another,  and  so  on  till  they  fix;  which  made  me 
conceive  that  each  bee  had  its  own  cell.  When  they  come  to  the 
intended  cell,  they  put  their  two  hind  legs  into  it,  with  the  tw'o  fore 
legs  and  the  trunk  out  on  the  mouth  of  the  neighbouring  cell,  and 
then  the  tail  or  belly  is  thrust  down  into  the  intended  cell ; they 
then  bring  the  leg  under  the  belly,  and  turning  the  point  of  the  tail 
to  the  outside  of  the  leg,  where  the  farina  is,  they  shove  it  off  by 
the  point  of  the  tail.  When  it  is  thus  shoved  off  both  legs,  the  bee 
leaves  it,  and  the  tw'o  pieces  of  farina  may  be  seen  lying  at  the  bot- 
tom of  the  cell ; another  bee  comes  almost  immediately',  and  creep- 
ing into  the  cell,  continues  about  five  minutes,  kneading  and  work- 
ing it  down  into  the  bottom,  or  spreads  it  over  what  was  deposited 
there  before,  leaving  it  a smooth  surface. 

It  is  of  a consistency  like  paste,  burns  slightly,  and  gives  a kind 
of  unusual  smell,  probably  from  having  been  mixed  with  animal 
juice  in  the  act  of  kneachng  it  dow'n,  for  when  brought  in  it  is 
rather  a powder  than  a paste.  That  it  is  the  food  of  the  maggot  is 

38 


434 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


proved  by  examining  the  animal’s  stomach  ; for  when  we  kill  a 
maggot  full  grown,  w'e  find  its  stomach  full  of  a similar  substance, 
only  softer,  as  if  mixed  with  a fluid,  but  we  never  find  honey  in  the 
stomach  ; therefore  we  are  to  suppose  it  is  collected  as  food  for  the 
maggot,  as  much  as  honey  is  for  the  old  bee.  Mr.  Schirach  ima- 
gines that  the  semen  of  the  male  is  the  food  of  the  maggot ; but 
the  food  of  the  male  and  the  queen  maggot  has  been  supposed  to 
be  difierent  from  that  of  the  labourers.  Reaumur  says  the  food  of 
the  queen  maggot  is  difierent  in  taste  from  that  of  the  common  ones. 
How  he  knew  this,  who  was  unacquainted  with  the  food  of  the 
others,  I cannot  conceive. 


Of  the  Excrement  of  the  Maggot. 

They  have  very  little  excrement,  but  what  they  do  discharge  is 
deposited  at  the  bottom  of  the  cell ; and  what  at  first  will  appear 
rather  extraordinary,  it  is  never  cleared  away  by  the  bees,  but  al- 
lowed to  dry  along  with  the  maggot  coats ; and  both  fresh  eggs  and 
honey  are  deposited  in  these  cells  so  circumstanced,  every  future 
year  ; so  that  in  time  the  cells  become  nearly  half  full. 


Of  the  Chrysalis  State. 

In  this  state  they  are  forming  themselves  for  a new'  life  ; they 
are  either  entirely  new  built,  or  wonderfully  changed,  for  there  is 
not  the  smallest  vestige  of  the  old  form  remaining;  yet  it  must  be 
the  same  materials,  for  now  nothing  is  taken  in.  How  far  this 
change  is  only  the  old  parts  new  modelled,  or  gradually  altering 
their  form,  is  not  easily  determined.  To  bring  about  the  change, 
many  parts  must  be  removed  out  of  which  the  new  ones  are  pro- 
bably formed.*  As  bees  are  not  different  in  this  state  from  the 

* [It  is  in  the  determination  of  these  interesting  questions  that  the  minute 
researches  of  Swammerdam  manifest  their  importance.  His  figures  demonstrate 
that  the  larva  of  the  bee  consists  of  thirteen  annular  segments,  of  which  one  cor- 
responds to  the  head,  three  to  the  thorax,  and  nine  to  the  abdomen  of  the  perfect 
insect. 

7’he  cephalic  segment  supports  the  rudimental  eyes,  which  resemble  the  ocelli 
of  other  insects  in  structure,  but  are  colourless  and  semitransparent.  The 
antennae  are  represented  by  two  small  organs  placed  at  the  anterior  angles  of  the 
head  ; the  oral  organs  are  also  indicated;  there  is  a small  transverse  upper  lip 
or  labrum,  beneath  which  are  two  little  horny  parts,  afterwards  destined  to 
become  the  mandibles:  then  “two  little  parts  which  seem  as  if  they  were  arti- 
culated” these  are  subsequently  developed  into  the  maxillse ; and  between  these 
is  a mesial  “small,  and  somewhat  prominent  part,  which  resembles  a trunk  or 
tongue,  and  this  increasing  by  degrees,  at  length  indeed  constitutes,”  says  Swam- 
merdam, “ the  trunk  of  the  bee.” 

We  thus  have  evidence  that  the  parts  which  so  conspicuously  distinguish  the 
imago  from  the  larva,  and  not  “entirely  new  built,”  but  are  “ wonderfully 
changed”  by  gradually  altering  their  form  and  relative  dimensions. 

With  respect  to  the  rest  of  the  larva,  we  find  that  the  body  is  furnished  on  each 
side  with  ten  minute  circular  spiracles,  a pair  being  placed  on  each  segment,  with 
the  exception  of  thtat  which  immediately  follows  the  head,  and  the  terminal  one 


OBSERVATIONS  ON  BEES. 


4^5 


common  flying  insects  in  genera],  I shall  not  pursue  the  subject  of 
their  changes  further;  although  it  makes  a very  material  part  in 
the  natural  history  of  insects. 

When  the  chrysalis  is  formed  into  the  complete  bee,  it  then  de- 
stroys the  covering  of  its  cell,  and  comes  forth.  The  time  it  con- 
tinues in  this  state  is  easier  ascertained  than  either  in  that  of  the 
egg  or  the  maggot;  for  the  bees  cannot  move  the  chrysalis  as  they 
do  the  two  others.  In  one  instance  it  was  thirteen  days  and  twelve 
hours  exactly;  so  that  an  egg  in  hatching  being  five  days,  the  age 
of  the  maggot  being  four  days,  and  the  chrysalis  continuing  thir- 
teen and  a half,  the  whole  makes  twenty-two  days  and  a half:  but 
how  far  this  is  accurate  I will^not  pretend  to  say.  I found  that  the 
chrysalis  of  a male  was  fourteen  days,  but  this  was  probably  acci- 
dental. When  they  first  come  out  they  are  of  a grayish  colour, 
but  soon  turn  brown. 

When  the  swarm  of  which  I have  hitherto  been  giving  the  his- 
tory has  come  off  early  and  is  a large  one,  more  especially  if  it 
was  put  into  too  small  a hive,  it  often  breeds  too  many  for  the  hive 
to  keep  through  the  winter  ; and  in  such  case  a new  swarm  is  throwm 
off,  which,  however,  is  commonly  not  a large  one,  and  generally 
has  too  little  time  to  complete  its  comb,  and  store  it  with  honey  suf- 
ficient to  preserve  them  through  the  winter.  This  is  similar  to  the 
second  or  third  swarm  of  the  old  hives. 


Of  the  Seasons  when  the  different  operations  of  Bees  tahe  place. 

I have  already  observed  that  the  new  colony  immediately  sets 
about  the  increase  of  their  numbers,  and  everything  relating  to  it. 
They  had  their  apartments  to  build,  both  for  the  purpose  of  breed- 
ing, and  as  a storehouse  for  provisions  for  the  winter.  When  the 
season  for  laying  eggs  is  over,  then  is  the  season  for  collecting  ho- 
ney ; therefore  when  the  last  chrysalis  for  the  season  comes  forth 
its  cell  is  immediately  filled  with  hone3^  and  as  soon  as  a cell  is  full 
it  is  covered  over  with  pure  wax,  and  is  to  be  considered  as  store 
for  the  winter.  This  covering  answers  tw'o  very  essential  purposes  : 
one  is  to  keep  it  from  spilling,  or  daubing  the  bees  ; the  other  to  pre- 
vent its  evaporation,  by  which  means  it  is  kept  fluid  in  such  a 
warmth.  They  are  also  employed  in  laying  up  a store  of  bee-bread 
for  the  young  maggots  in  the  spring,  for  they  begin  to  bring  forth 

which  bears  the  arms.  Previous  to  shedding'  the  skin,  the  first  three  segments 
of  the  body  begin  t®  swell,  and  make  room  for  the  aggregated  muscles  which  are 
to  put  in  motion  the  locomotive  organs,  attached,  in  the  perfect  insect,  exclu- 
sively to  these  segments. 

The  larva  being  apodal,  both  the  legs  and  wings  may  be  regarded  as  being 
“ entirely  new  built,”  and  the  pupa  of  the  bee  then  presents  an  elegant  disposition 
and  well-ordered  representation  of  all  the  limbs  and  parts  of  the  future  bee.  The 
antennae  and  the  tongue  are  seen  lying  along  the  breast,  and  the  wings  and  legs 
bent  from  the  sides  of  the  thorax  along  the  belly.  Some  of  the  segments  of  the 
larva  are  “ removed,”  and  out  of  these  the  organs  of  generation  appear  to  be 
formed.] 


43G 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


much  earlier  tiian  probably  any  other  insect,  because  they  retain 
a summer  heat  and  store  up  food  for  the  young. 

In  the  month  of  August  we  may  suppose  the  queen  or  queens  are 
impregnated  by  the  males  ; and  as  the  males  do  not  provide  for 
themselves,  they  become  burdensome  to  the  workers,  and  are  there- 
fore teazed  to  death  much  sooner  than  they  otherwise  would  die ; 
and  when  the  bees  set  about  this  business  of  providing  their  winter 
store,  every  operation  is  over,  except  the  collecting  of  honey  and 
bee-bread.  At  this  time  it  would  seem  as  if  the  males  were  con- 
scious of  their  danger,  for  they  do  not  rest  on  the  mouth  of  the  hive 
in  either  going  out  or  coming  in,  but  hurry  cither  in  or  out;  how- 
ever they  are  commonly  attacked  by  one,  two,  or  three  at  a time: 
lhc_v  seem  to  make  no  resistance,  only  getting  away  as  fast  as  pos- 
sible. The  labourers  do  not  sting  them,  only  pinch  them,  and  pull 
them  about  as  if  to  wear  them  out;  but  I suspect  it  may  be  called 
as  much  a natural  as  a violent  death. 

The  whole  of  the  males  are  now  destroyed,  and  indeed  it  would 
have  been  useless  to  have  saved  any  to  impregnate  the  queen  in  the 
spring.  That  there  may  be  many  more  than  may  be  wanted  I can 
easily  believe,  for  this  we  see  throughout  nature ; but  she  always 
times  her  operations  well,  although  there  may  be  supernumeraries. 

When  the  young  are  wholly  come  forth,  and  either  the  cells  en- 
tirely filled,  or  no  more  honey  to  be  collected,  then  is  the  time  or 
season  for  remaining  in  their  hives  for  the  winter. 

Although  I have  now  completed  a hive,  and  no  operations  are 
going  on  in  the  winter  months,  yet  the  history  of  this  hive  is  imper- 
fect till  it  sends  forth  a new  swarm. 

As  the  common  bee  is  very  susceptible  of  cold,  we  find  as  soon 
as  the  cold  weather  sets  in  they  become  very  quiet  or  still,  and  re- 
main so  throughout  the  winter,  living  on  the  produce  of  the  summer 
and  autumn  ; and  indeed  a cold  day  in  the  summer  is  sufficient  to 
keep  them  at  home  more  so  than  a shower  in  a warm  day;  and  if 
the  hive  is  thin  and  much  exposed,  they  will  hardly  move  in  it,  but 
get  as  close  together  as  the  comb  will  let  them,  into  a cluster.  In 
this  manner  they  appear  to  live  through  the  winter;  however,  in  a 
fine  day  they  become  very  lively  and  active,  going  abroad,  and 
appearing  to  enjoy  it,  at  which  time  they  get  rid  of  their  excre- 
ment; for  I fancy  they  seldom  throw  out  their  excrement  when  in 
the  hive.  To  prove  this,  I confined  some  bees  in  a small  hive,  and 
fed  them  with  honey  for  some  days,  and  the  moment  I let  them  out 
they  flew,  and  threw  out  their  excrement  in  large  quantities  ; and 
therefore  in  the  winter,  I presume,  they  retain  the  contents  of  their 
bowels  for  a considerable  time.  Indeed,  when  we  consider  their 
confinement  in  the  winter,  and  that  they  have  no  place  to  deposit 
their  excrement,  we  can  hardly  account  for  the  whole  of  this 
operation  in  them.  Tlieir  excrement  is  of  a yellow  colour,  and 
according  to  their  confinement  it  is  found  higher  and  higher  up  in 
the  intestine,  almost  as  high  as  the  crop. 

Their  life  at  this  season  of  the  year  is  more  uniform,  and  may 


OBSERVATIONS  ON  BEES. 


437 


be  termed  simple  existence,  till  the  warm  weather  arrives  again. 
As  they  now  subsist  on  their  summer’s  industry,  they  would  seem 
to  feed  in  proportion  to  the  coldness  of  the  season  ; for  from  expe- 
riment I found  the  hive  grow  tighter  in  a cold  week  than  it  did 
in  a warmer,  which  led  to  further  experiments.  I first  made  an 
experiment  upon  a bee-hive,  to  ascertain  the  quantity  of  honey 
lost  through  the  winter.  The  hive  was  put  into  the  scale 
November  3,  1776, 

oz.  drams. 

November  lOtb,  it  had  lost  2 7 


17th,  4 2i 

24th, 3 7i 

December  1st, 8 2 

8th,  2 1 

15th,  5 2 

22d, 4 3 

29th, 5 4 

1777.  January  1st,  2 5 

12th, 5 2 

19th, 3 4 

26th, 3 li 

February  2d, 5 0 

9th,  7 0 


The  whole  72  1§ 


Although  an  indolent  state  is  very  much  the  condition  of  bees 
through  the  winter,  yet  progress  is  making  in  the  queen  towards  a 
summer  increase.  The  eggs  in  the  oviducts  are  beginning  to  swell, 
and  I believe  in  the  month  of  March  she  is  ready  to  lay  them,  for 
the  young  bees  are  to  swarm  in  June;  which  constitutes  the  queen 
bee  to  be  the  earliest  breeder  of  any  insect  we  know.  In  conse- 
quence of  this,  the  labourers  become  sooner  employed  than  any 
other  of  this  tribe  of  insects.  This  both  queen  and  labourers  are 
enabled  to  accomplish,  from  living  in  society  through  the  winter; 
and  it  becomes  necessary  in  them,  as  they  have  their  colony  to 
form  early  in  the  summer,  which  is  to  provide  for  itself  for  the 
winter  following.  All  this  requires  the  process  to  be  carried  for- 
ward earlier  than  by  any  other  insects,  for  these  are  only  to  have 
young  which  ai’e  to  take  care  of  themselves  through  the  summer, 
not  being  under  the  necessity  of  providing  for  the  winter. 

In  the  month  of  April  I found  in  the  cells  young  bees,  in  all  stages, 
from  the  egg  to  the  chrysalis  state,  some  of  which  were  changed  in 
colour,  therefore  were  nearly  arrived  at  the  fly  state,  and  probably 
some  might  have  flown. 

As  this  season  is  too  early  for  collecting  the  provision  of  the 
maggot  abroad,  the  store  of  farina  comes  now  into  use ; but  as  soon 
as  llowers  begin  to  blow,  the  bees  gather  the  fresh,  although  they 
have  farina  in  store,  giving  the  fresh  the  preference. 

38^^ 


438 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Of  the  Queen. 

The  queen  bee,  as  she  is  termed,  has  excited  more  curiosity  than 
all  the  others,  although  much  more  belongs  to  the  labourers.  From 
the  number  of  these,  and  from  their  exposing  themselves,  they  have 
their  history  much  better  made  out ; but  as  there  is  only  one  queen, 
and  she  scarcely  ever  seen,  it  being  only  the  effects  of  her  labour 
we  can  come  at,  an  opportunity  has  been  given  to  the  ingenuity  of 
conjecture,  and  more  has  been  said  than  can  well  be  proved.  She 
is  allowed  to  be  bred  in  the  common  way,  only  that  there  is  a 
peculiar  cell  for  her  in  her  first  stage;  and  Reaumur  says,  “her 
food  is  different  when  in  the  maggot  state;”  but  as  there  is 
probably  but  one  queen,  that  the  whole  might  not  depend  on  one 
life,  it  is  asserted  that  the  labourers  have  a power  of  forming  a 
common  maggot  into  a queen.  If  authors  had  given  us  this  as  an 
opinion  only,  we  might  have  passed  it  over  as  improbable  ; but 
they  have  endeavoured  to  prove  it  by  experiments,  which  require 
to  be  examined.  And  for  that  purpose  I shall  give  what  they  say 
on  that  head,  with  my  remarks  upon  it. 

,0.bstr acts  from  Mr.  Schirach. 

The  following  experiments  were  made  to  ascertain  the  origin  of 
the  queen  bee: — “In  twelve  wooden  boxes  were  placed  twelve 
pieces  of  comb,  four  inches  square,  each  containing  both  eggs  and 
maggots,  so  suspended  that  the  bees  could  come  round  every  part 
of  the  comb:  in  each  box  was  shut  up  a handful  of  working  bees. 
Knowing  that  when  bees  are  forming  a queen  they  should  be  con- 
fined,* the  boxes  were  kept  shut  for  two  days.  When  examined 
at  the  end  of  that  period  (six  boxes  only  were  opened),  in  all  of 
them  royal  cells  were  begun,  one,  two,  or  three  in  each;  all  of 
these  containing  a maggot  four  days  old.  In  four  days,  the  other 
six  boxes  were  opened,  and  royal  cells  found  in  each,  containing 
maggots  five  days  old,  surrounded  by  a large  provision  of  jelly; 
and  one  of  these  maggots  examined  in  the  mircroscope,  in  every 
respect  resembled  a working  bee. 

“ This  experiment  was  repeated,  and  the  maggots  selected  to  be 
made  queens  were  three  days  old  ; and  in  seventeen  days  there 
w'ere  found  in  the  twelve  boxes  fifteen  livel}',  handsome  queens.f 
These  experiments  were  made  in  May,  and  the  bees  were  allowed 
to  work  great  part  of  the  summer  ; the  bees  were  examined  one 

* How  he  came  to  know  this  I cannot  conceive,  for  nothing  a priori  could  give 
such  information. 

I Now  this  account  is  not  only  improbabie,  but  it  does  not  laily  with  itself. 
First,  it  is  not  probabie  that  a handfui  of  bees  shouid  or  would  set  about  making 
two,  tliree,  or  four  queens,  when  we  do  not  find  that  number  in  a large  hive; 
and  secondly,  it  seems  inconsistent  that  only  fifteen  should  be  formed  out  of 
twelve  parcels,  when  some  of  the  former  parcels  had  four  young  queens. 


OBSERVATIONS  ON  BEES, 


43d 


by  one,  but  no  drone  could  be  discovered,  and  yet  the  queens  were 
impregnated,  and  laid  their  eggs.* * * § 

“The  above  experiment  was  repeated  with  pieces  of  conib  con- 
taining eggs  only,  in  six  boxes,  but  no  preparations  were  made 
towards  producing  a queen.f 

“ The  experiment  of  producing  a queen  bee  from  a maggot  was 
repeated  every  month  of  the  year,  even  in  Novernber.J 

“A  maggot  three  days  old  w'as  procured  from  a friend,  inclosed 
in  an  ordinary  cell,  and  shut  up  with  a piece  of  comb,  containing 
eggs  and  maggots.  That  three  days  old  was  formed  into  a queen, 
and  all  the  other  maggots  and  eggs  were  destroyed. § 

“ In  above  a hundred  experiments  a queen  has  been  formed  from 
maggots  three  days  old.”|| 

VVilhelmi  observes  that  a queen  cell,  which  is  made  while  the 
bees  are  shut  up,  is  formed  by  breaking  down  three  common  cells 
into  one,  when  the  maggot  is  placed  in  the  centre,  after  which  the 
sides  are  repaired. 

A young  queen  lately  hatched  was  put  into  a hive,  which  had 
been  previously  ascertained  to  contain  no  drones,  and  whose  queen 
W’as  removed  ; and  yet  the  young  queen  laid  eggs.*1T  In  repeating 
Mr.  Schirach’s  experiment,  he  shut  up  four  pieces  of  comb,  with 
one  maggot  in  each ; after  two  days  the  maggot  were  all  dead, 
and  the  bees  had  desisted  from  labour.** 

A piece  of  comb  from  which  all  the  eggs  and  maggots  had  been 
removed,  was  shut  up  with  some  honey  and  a certain  number  of 
workers  : in  a short  time  they  became  very  busy,  and  upon  the 
evening  of  the  second  day  three  hundred  eggs  were  found  in  the 
cells.ff  He  repeated  this  experiment  with  the  same  result,  and  the 
bees  were  left  to  themselves;  they  placed  queen  maggots  in  the 
queen  cells,  newly  constructed,  and  others  in  male  cells;  the  rest 

* Here  is  a wonder  of  another  kind  ; queens  laying  eggs,  which  (we  must  sup- 
pose Mr.  Schirack  meant  we  should  believe)  they  hatched,  without  the  influence 
of  the  male. 

f Why  eggs,  which  we  must  conceive  hatched,  and  produced  maggots,  did  not 
form  queens,  one  cannot  imagine. 

ij;  In  which  month,  as  bees  never  swarm,  there  could  be  no  occasion  for  mothers, 
or  supernumerary  queens,  and  still  each  experiment  produced  a handsome 
queen.  This  is  as  singular  an  observation  as  any.  In  this  country,  and  in  all 
similar  ones,  bees  hardly  breed  after  July,  and  by  the  beginning  of  September 
there  is  hardly  a chrysalis  to  be  seen  ; yet  these  bred  till  November,  and  even 
laid  eggs. 

§ Why  did  the  bees  destroy  them  in  this  experiment,  and  not  in  others'? 

II  The  working  bees  from  the  above  experiments  are  considered  as  all  females, 
although  the  ovaria  are  too  small  for  examination. 

It  would  appear  that  a maggot  three  days  old  was  of  the  best  age  for  this  ex- 
periment, yet  one  should  have  conceived  that  a maggot  two  days  old  would  soon 
be  fit. 

^ There  is  no  mystery  in  tliis ; but  did  they  hatch  ? 

**  I’his  is  the  most  probable  event  in  the  whole  experiments. 

If  This  would  show  that  labourers  can  be  changed  into  queens  at  will,  and  that 
neither  they  nor  their  eggs  require  to  be  impregnated  ; if  this  was  the  case,  there 
would  be  no  occasion  for  all  the  push  in  making  a queen  or  a male. 


440 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


were  left  undisturbed.  He  again  took  two  pieces  of  comb  which 
contained  neither  eggs  nor  maggots,  and  shut  them  up  with  a cer- 
tain number  of  workers,  and  carried  the  box  into  a stove  ; next 
evening,  one  of  the  pieces  of  comb  contained  several  eggs,  and  the 
beginning  of  a royal  cell  that  was  empty'. 

Besides  the  short  observations  contained  in  the  notes,  I beg  leave 
to  observe  that  I have  my  doubts  respecting  the  whole  of  these 
experiments,  from  several  circumstances  which  occurred  in  mine. 
The  tlu’ee  following  facts  appear  much  against  their  probability; 
first,  a summer’s  evening  in  this  country  is  commonly  too  cold  for 
so  small  a parcel  of  bees  to  be  lively,  so  as  to  set  about  new  opera- 
tions; they  get  so  benumbed  that  they  hardly  recover  in  the  day, 
and  I should  suspect  that  where  these  experiments  were  made  (and 
indeed  some  are  said  to  have  been  tried  in  this  country),  it  is  also 
too  cold  : secondly,  if  the  weather  should  happen  to  be  so  warm  as 
to  prevent  this  eflect,  then  they  are  so  restless  that  they  commonly 
destroy  themselves;  or  wear  themselves  out;  at  least,  after  a few 
days’  confinement  we  find  them  mostly  dead  : and  thirdly,  the  ac- 
count given  of  the  formation  of  a royal  cell,  without  mentioning  the 
above  inconvenience,  which  is  natural  to  the  experiment,  makes  me 
suspect  the  whole  to  be  fabricated.  To  obviate  the  first  objection 
which  I found  from  experiment  to  prevent  any  success  that  other- 
wise might  arise,  I put  my  parcel  of  bees,  with  their  comb,  in  which 
W'ere  eggs,  as  also  maggots,  and  in  some  of  the  trials  there  were 
chrysalises,*  into  a warmer  place,  such  as  a glass  frame  over  tan, 
the  surface  of  which  was  covered  with  mould  to  prevent  the  rising 
of  unwholesome  air;  but  from  knowing  that  the  maggot  was  fed 
with  bee-bread,  or  farina,  I took  care  to  introduce  a cell  or  two 
with  this  substance,  as  also  the  flowers  of  plants  that  produce  a 
great  deal  of  it,  likewise  some  honey  for  the  old  ones.  In  this 
state  rny  bees  were  preserved  from  the  cold,  as  also  provided  with 
necessaries;  but  after  being  confined  several  days,  upon  opening 
the  door  of  the  hive,  what  were  alive  came  to  the  door,  walked 
and  flew  about,  but  gradually  left  it,  and  on  examining  the  combs, 
&c.,  I found  the  maggots  dead,  and  nothing  like  any  operation 
going  on. 

The  queen,  the  mother  of  all,  in  whatever  way  produced,  is  a true 
female,  and  diflerent  from  both  the  labourers  and  the  male.  She  is 
not  so  large  in  the  trunk  (abdomen)  as  the  male,  and  appears  to  be 
rather  larger  in  every  part  than  the  labourers.  The  scales  on  the 
under  surface  of  the  belly  of  the  labourers,  are  not  uniformly  of  the 
same  colour  over  the  whole  scale  ; that  part  being  lighter  which  is 
overlapped  by  the  terminating  scale  above,  and  the  uncovered  part 

* I choose  to  have  some  chrysalises,  for  I supposed  tliat  if  my  bees  died  or  flew 
away,  the  chrysalises  when  they  came  nut,  which  would  happen  in  a few  days, 
not  knowing  where  to  go,  might  stay  and  take  care  of  the  maggots  that  might  be 
hatched  from  the  egg;  but  to  my  surprise,  I found  that  neither  the  eggs  hatched, 
nor  did  the  chrysalises  come  forth  ; all  died  ; from  which  I began  to  suspect 
that  the  presence  of  the  bees  was  necessary  for  both. 


OBSERVATIONS  ON  BEES. 


441 


being  darker  ; this  light  part  does  not  terminate  in  a straight  line, 
but  in  two  curves,  making  a peak,  ail  which  gives  the  belly  a lighter 
colour  in  the  neiglibouring  bees  ; more  especially  when  it  is  pulled 
out  or  elongated. 

The  tongue  of  the  female  is  considerably  shorter  than  that  of  the 
labouring  bee,  more  like  that  of  the  male ; however,  the  tongues  of 
the  labourers  are  not  in  all  of  an  equal  length,  but  none  have  it  so 
short  as  the  queen. 

The  size  of  the  belly  of  the  femalis  of  such  animals  varies  a little, 
according  to  the  condition  they  are  in ; but  the  belly  of  the  male 
and  the  labourer  has  but  little  occasion  to  change  its  size,  as  they 
are  at  all  times  nearly  in  the  same  condition  with  regard  to  fat, 
having  always  plenty  of  provision  ; but  the  true  female  varies  ver\' 
considerably;  she  is  of  a difterent  size  and  shape  in  the  summer  to 
what  she  is  in  the  winter;  and  in  the  winter  she  has  what  may  be 
called  her  natural  size  and  shape ; she  is  upon  the  whole  rather 
thicker  than  the  labourer,  and  this  thickness  is  also  in  the  belly, 
which  probably  arises  from  the  circumstance  of  the  oviduct  being 
in  the  winter  pretty  large,  and  the  reservoir  for  semen  full.  The 
termination  of  the  belly  is  rather  more  peaked  than  in  the  labourers, 
the  last  scale  being  rather  narrow  from  side  to  side,  and  coming 
more  to  a point  at  tlie  anus.  The  scales  at  this  season  are  more 
overlapped,  which  can  only  be  known  by  drawing  them  out.  In 
the  spring  and  summer  she  is  more  easily  distinguished;  the  belly 
is  not  only  thicker,  but  considerably  longer  than  formerly,  which 
arises  from  the  increase  of  the  eggs.  We  distinguish  a queen  from 
the  working  bee  simply  by  size,  and  in  some  degree  by  colour; 
but  this  last  is  not  so  easily  ascertained,  because  the  diflerence  in 
the  colour  is  not  so  remarkable  in  the  back,  and  the  only  view  wo 
can  commonly  get  of  her  is  on  this  part;  but  when  a hive  is  killed, 
the  best  way  is  to  collect  all  the  bees,  and  spread  them  on  white 
paper,  or  put  them  into  water  in  a broad,  flat-bottomed,  shallow 
white-dish,  in  which  they  seem  ; and  by  looking  at  them  singly, 
she  may  be  discovered.  As  the  queen  breeds  the  first  year  she  is 
produced,  and  the  oviducts  never  entirely  subside,  an  old  queen  is 
probably  thicker  than  a new-bred  one,  unless  indeed  the  oviducts 
and  the  eggs  form  in  the  chrysalis  state,  as  in  the  silk-worm,  which 
I should  suppose  they  did.  The  queen  is  perhaps  at  the  smallest 
size  just  as  she  has  done  breeding,  for  as  she  is  to  lay  eggs  by 
the  month  of  March,  she  must  begin  early  to  fill  again  ; bui  I 
believe  her  oviducts  are  never  emptied,  having  at  all  times  eggs  in 
them,  although  but  small.  She  has  fat  in  her  belly,  similar  to  the 
other  bees. 

It  is  most  probable  that  the  queen  which  goes  off  with  the  swarm 
is  a young  one,  for  the  males  go  off  with  the  swarm  to  impregnate 
her,  as  she  must  be  impregnated  the  same  year,  because  she  breeds 
the  same  year. 

The  queen  has  a sting  similar  to  the  working  bee. 


442 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


Of  the  JVurnbe?'  of  Queens  in  a Hive. 

I believe  a hive  or  swarm  has  but  one  queen,  at  least  I have 
never  found  more  than  one  in  a swarm,  or  in  an  old  hive  in  the 
winter;  and  probably  this  is  what  constitutes  a hive  ; for  when 
there  are  two  queens,  it  is  likely  that  a division  may  begin  to  take 
place.  Supernumerary  queens  are  mentioned  by  Riem,  who  asserts 
he  has  seen  them  killed  by  the  labourers,  as  well  as  the  males. 

INovember  18th,  1788,  I killed  a hive  that  had  not  swarmed  the 
summer  before,  and  which  was  to  appearance  ready  to  swarm  every 
day;  but  when  I supposed  the  season  for  swarming  was  over,  and 
it  had  not  swarmed,  I began  to  suspect  that  the  reason  why  it  did 
not  was  owing  to  there  being  no  young  queen  or  queens  ; and  I 
found  only  one.  This  is  a kind  of  presumptive  proof  that  I was 
right  in  my  conjecture;  unless  it  be  supposed,  that  when  they  were 
determined  not  no  swarm,  they  destroyed  every  queen  except  one. 
In  a hive  that  died,  I found  no  males,  and  only  one  queen.  This 
circumstance,  that  so  few  queens  are  bred,  must  arise  from  the 
natural  security  the  queen  is  in  from  the  mode  of  their  society  ; for 
although  there  is  but  one  queen  in  a wasp’s,  hornet’s,  and  humble 
bee’s  nest  or  hive,  yet  these  breed  a great  number  of  queens;  the 
wasp  and  hornet  some  hundreds;  but  not  living  in  society  during 
the  winter,  they  are  subject  to  great  destruction,  so  that  probably 
not  one  in  a hundred  lives  to  breed  in  the  summer.  I have  said 
that  the  queen  leaves  off  laying  in  the  month  of  July ; and  now  she 
is  to  be  impregnated  by  the  males  before  they  die.  Mr.  Riem  as- 
serts, he  has  seen  the  copulation  between  the  male  and  the  female, 
but  does  not  say  at  what  season.  I should  doubt  this ; but  Mr. 
Schirach  supposes  the  queen  impregnated  without  copulation.  I 
know  not  whether  he  means  by  this  that  she  is  not  impregnated  at 
all,  and  supposes,  like  Mr.  Debraw,  that  the  eggs  are  impregnated 
after  they  are  laid,  by  a set  of  small  drones,  who  pass  over  the 
cells,  and  thrust  their  tails  down  into  the  cell,  so  as  to  besmear  the 
egg.’^  Mr.  Bonnet  does  not  consider  it  necessaiy  that  the  drones 
should  be  small  for  this  purpose,  for  he  saw  a large  drone  passing 
over  the  cells  of  a piece  of  comb,  stopping  at  every  one  which  con- 
tained an  egg,  but  at  no  other,  and  giving  a knock  with  his  tail  on 
the  mouth  of  the  cell  three  times;  this  he  supposed  was  the  mode 
of  impregnating  the  eggs.  The  number  three  has  always  been  a 
famous  number;  but  it  will  not  do  where  there  are  no  males,  which 
is  the  case  of  a hive  in  the  spring,  the  time  when  the  queen  is  most 
employed  in  laying  eggs;  which  made  him  suppose  the  use  of  the 
males  was  to  feed  the  maggots  with  their  semen.  It  is  probable 
that  the  copulation  is  like  that  of  most  other  insects.  The  copula- 
tion of  the  humble  bee  I have  seen,  it  is  similar  to  the  common  fly. 
The  sting  is  extended  at  the  time,  and  turned  up  on  the  back,  be- 

* Mr.  Debraw,  knowing  the  drones  died  in  the  latter  end  of  summer  or  the 
autumn,  was  obliged  to  suppose  a small  set  of  males,  that  lived  through  the  win- 
ter, for  that  purpose.  ' 


OBSERVATIONS  ON  BEES. 


443 


tween  the  tw'o  animals ; they  are  some  4irae  in  this  act.  In  the 
hornet  it  is  the  same.  The  circumstances  relative  to  the  impreg- 
nating the  queen  not  being  known,  great  room  has  been  given  for 
conjecture,  which,  if  authors  had  presented  as  conjectures  only,  it 
would  have  shown  their  candour  ; but  they  have  given,  W’hat  in 
them  were  probably  conceits,  as  facts. 

Of  the  Male  Bee. 

The  male  bee  is  considerably  larger  than  the  labourers : he  is 
even  larger  than  the  queen,  although  not  so  long  when  she  is  in  her 
full  state  with  eggs:  he  is  considerably  thicker  than  either,  but  not 
longer  in  the  same  proportion:  he  does  not  terminate  at  the  anus 
in  so  sharp  a point ; and  the  opening  between  the  two  last  scales 
of  the  back  and  belly  is  larger,  and  more  under  the  belly  than  in  the 
female.  His  proboscis  is  much  shorter  than  that  of  the  labouring 
bee,  which  makes  me  suspect  he  does  not  collect  his  own  honey, 
but  takes  that  which  is  brought  home  by  the  others ; especially  as 
W’e  never  find  the  males  abroad  on  flowers,  &c.,  only  flying  about 
the  hives  in  hot  weather,  as  if  taking  an  airing;  and  when  we  find 
that  the  male  of  the  humble  bee,  which  collects  its  own  food,  has 
as  long  a proboscis  or  tongue  as  the  female,  I think  it  is  from  all 
these  facts  reasonable  to  suppose  the  male  of  the  common  bee  feeds 
at  home.  He  has  no  string. 

The  males,  I believe,  are  later  in  being  bred  than  the  labouring 
bee.  As  they  are  only  produced  to  go  off  with  a hive,  they  are 
not  so  early  brought  forth  ; for  in  the  month  of  April  I killed  a hive, 
in  which  I found  maggots  and  chrysalises,  but  did  not  find  any 
males  among  the  latter  : the  maggots  are  too  young  for  such  inves- 
tigation ; but  about  the  20th  of  May  we  observed  males  : they  are 
all  very  much  of  the  same  size.  In  the  month  of  August,  probably 
about  the  latter  end,  we  may  suppose  they  impregnate  the  queen 
for  the  next  year,  and  about  the  latter  end  of  the  same  month,  and 
beginning  of  September,  they  are  dying,  but  seem  to  be  hastened  to 
their  end  by  the  labourers.  In  1791,  as  early  as  the  19th  of  June, 
I saw  the  labourers  killing  the  males  of  a hive,  or  rather  of  a 
swarm,  that  has  not  yet  swarmed,  but  was  hanging  out;  this,  how- 
ever, w'as  out  of  the  common  course.  They  appear  to  be  sensible 
of  their  fate,  for  they  hurry  in  and  out  of  the  hive  as  quick  as  pos- 
sible, seemingly  with  a view  to  avoid  the  labourers ; and  we  find 
them  attacked  by  the  labourers,  who  pinch  them  with  their  for- 
ceps, and  when  they  are  so  hurt,  and  fatigued  with  attempts  to 
make  their  escape,  as  not  to  be  able  to  fly,  they  are  thrown  over 
on  the  ground  and  left  to  die.  That  this  is  the  fate  of  every  male 
bee  is  easily  ascertained,  by  examining  every  bee  in  the  hive  when 
killed  for  the  honey,  which  is  after  this  season  ; no  male  being  then 
found  in  it.  Bonnet  supposes  them  starved  to  death,  as  he  never 
saw  wounds  on  them.  In  the  course  of  a winter  I have  killed 
several  hives,  some  as  late  as  April,  and  in  such  a way  as  to  pre- 


444 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


serve  every  bee,  and  after  examining  every  one  entirely,  I never 
perceived  one  male  of  any  kind  ; although  it  has  been  asserted  there 
arc  two  sizes  of  males,  and  that  the  small  are  preserved  through  the 
winter  to  impregnate  the  queen. 

Of  the  Labouring  Bee. 

This  class,  for  we  cannot  call  it  either  sex  or  species,  is  the 
largest  in  number  of  the  whole  community;  there  are  thousands  of 
them  to  one  queen,  and  pi'obahly  some  hundreds  to  each  male,  aS 
we  shall  see  by  and  by.  It  is  to  be  supposed  they  are  the  only  bees 
which  construct  the  whole  liive,  and  that  the  queen  has  no  other  bu- 
siness but  to  lay  the  eggs  : they  are  the  only  bees  that  bring  in  ma- 
terials ; the  only  ones  we  observe  busy  abroad;  and,  indeed,  the 
idea  of  any  other  is  ridiculous,  when  we  consider  the  disproportion 
in  numbers  as  well  as  the  employment  of  the  others,  while  the  work- 
ing bee  has  nothing  to  take  off  its  attention  to  the  business  of  the 
family.  They  are  smaller  than  either  the  queen  or  the  males:  not 
all  of  equal  size,  although  the  difference  is  not  very  great. 

The  queen  and  the  working  bees  are  so  much  alike  that  the  lat- 
ter would  seem  to  be  females  on  a different  scale  : however,  this 
difference  is  not  so  observable  in  the  bedinninsc  of  winter  as  in  the 
spring,  when  the  queen  is  full  of  eggs.  They  are  all  females  in  con- 
struction, having  tlie  female  parts,  which  are  extremely  small,  and 
would  be  easily  overlooked  by  a person  not  very  well  acquainted 
with  the  parts  in  the  queen : this  has  been  observed  by  Mr.  Riem  ; 
indeed,  one  might  suppose  that  they  were  only  young  queens,  and 
that  they  became  queens  after  a certain  age ; but  this  is  not  the  case. 
They  all  have  stings,  which  is  another  thing  that  makes  them 
similar  to  the  queen.  From  their  being  furnished  with  an  instru- 
ment of  defence  and  offence,  they  are  endowed  with  such  powers 
of  mind  as  to  use  it,  their  minds  being  extremely  irritable;  so  much 
so  that  they  make  an  attack  when  not  meddled  with,  simply  upon 
suspicion,  and  when  they  do  attack  they  always  sting ; and  yet, 
from  the  circumstance  of  their  not  being  able  to  disengage  the  sting, 
one  should  suppose  they  would  be  more  cautious  in  striking  with  it. 
When  they  attack  one  anothe" y seldom  use  it,  only  their  pin- 
cers : yet  I saw  two  bees  engaged,  and  one  stung  the  other  in  the 
mouth,  or  thereabouts,  and  the  sting  was  drawn  from  the  body  to 
which  it  belonged,  and  the  one  who  was  stung  ran  very  quickly 
about  with  it;  but  I could  not  catch  that  bee  to  observe  how  the 
sting  was  situated. 

As  they  are  the  collectors  of  honey,  much  more  than  what  is  for 
theii'  own  use,  either  itnmediately  or  in  future,  their  tongue  is  pro- 
portionably  fitted  for  that  purpose  : it  is  considerably  longer  than 
that  of  either  the  queen  or  the  male,  which  fits  them  to  take  up  the 
honey  from  the  hollow  parts  of  flowers,  of  considerable  depth. 
The  mechanism  is  very  curious,  as  will  be  explained  further  on. 


OBSERVATIONS  ON  BEES. 


445 


The  number  of  labourers  in  a hive  varies  very  considerably. 

In  one  hive  that  I killed  there  were  ....  3338 

In  another  .........  4472 

In  one  that  died  there  were  ......  2432 

That  I might  guess  at  the  number  of  bees  from  a given 
bulk,  I counted  what  number  an  alehouse  pint  held,  when 
wet,  and  found  it  contained  . . . . .2160 

Therefore,  as  some  swarms  will  fill  two  quarts,  such  must 

consist  of  near  .......  9000 

Of  the  Parts  concerned  in  the  Nourishment  of  the  Bee. 

Animals  which  only  swallow  food  for  themselves,  or  whose 
alimentary  organs  are  fitted  wholly  for  their  own  nourishment,  have 
them  adapted  to  that  use  only;  but  in  many,  these  organs  are  com- 
mon for  more  purposes,  as  in  the  pigeon,  and  likewise  in  the  bee. 
In  this  last,  some  of  the  parts  are  used  as  a temporary  reservoir, 
holding  both  that  which  is  for  the  immediate  nourishment  of  the 
animal,  and  also  that  which  is  to  be  preserved  for  a future  day,  in 
the  cells  formerly  described ; this  last  portion  is  therefore  thrown 
up  again,  or  regurgitated.  As  it  is  the  labourers  alone  in  the  com- 
mon bee  that  are  so  employed,  we  might  conceive  this  reservoir 
would  belong  only  to  them;  but  both  the  queen  and  males,  both  in 
the  common  and  humble  bee,  have  it,  as  also,  I believe,  every  one 
of  the  bee  tribe. 

As  the  bee  is  a remarkable  instance  of  regurgitation,  it  is  neces- 
sary the  structure  of  the  parts  concerned  in  this  operation,  and 
which  are  also  connected  with  digestion,  should  be  well  considered. 
Ruminating  animals  may  be  reckoned  regurgitating  animals,  but  in 
them  it  is  for  the  purpose  of  digestion  entirely  in  themselves.  But 
many  birds  may  be  called  regurgitating  animals,  and  in  them  it  is 
for  the  purpose  of  feeding  their  young.  Crows  fill  their  fauces, 
making  a kind  of  craw,  out  of  which  they  throw  back  the  food 
when  they  feed  their  3'oung ; but  the  most  remarkable  is  the  dove 
tribe,  who  first  fill  their  craw,  and  then  throw  it  up  into  the  beak  of 
their  young.*  The  bee  has  this  power  to  a remarkable  degree,  not 
however  for  the  purpose  of  feeding  the  young,  but  it  is  the  mode  of 
depositing  their  store  in  the  cells  when  brought  home. 

In  none  of  the  above-mentioned  regurgitating  animals  are  the 
reservoirs  containing  the  food  the  immediate  organ  of  digestion  ; 
nor  does  the  reservoir  for  the  honey  in  the  bee  appear  to  be  its 
stomach. 

The  tonguef  of  the  bee  is  the  first  of  the  alimentary  organs  to  be 

* See  Observations  on  certain  parts  of  the  Animal  QHconomy,  p.  191  [p.  149 
of  the  present  edition]. 

I The  part  which  Hunter  so  calls  includes  the  maxill®  and  their  rudiinental 
palpi,  the  labium  and  its  palpi,  as  well  as  the  tongue  properly  so  called,  which 
seems,  indeed,  to  be  strictly  an  inordinate  development  of  the  labium,  or  lower 

39 


440 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


considered  : it  is  of  a peculiar  structure,  and  is  probably  the  largest 
tongue  of  any  animal  we  know', for  its  size.  It  may  be  said  to  con- 
sist of  three  parts  respecting  its  length,  having  three  articulations. 
One,  its  articulation  with  the  head,  which  is  in  some  measure 
similar  to  our  larynx  {rnentum).  Then  comes  the  body  of  the  tongue, 
which  is  composed  of  two  parts;  one,  a kind  of  (labium), 
on  which  the  other,  or  true  tongue  (lingua),  is  articulated.  The 
first  ])art  (labium)  is  principally  a horny  substance,  in  which  there 
is  a groove,  and  it  is  articulated  w'ith  the  first  or  larynx  (rnentum)-, 
on  the  end  of  this  is  fixed  the  true  tongue,  with  its  different  parts. 
These  two  parts  of  the  tongue  are  as  it  were  inclosed  laterally  by 
two  horny  scales  (maxillce),  one  on  each  side,  which  are  concave 
on  that  side  next  to  the  tongue;  one  edge  is  thicker  than  the  other, 
and  they  do  not  extend  so  far  as  the  other  parts.  Each  of  these 
scales  is  composed  of  two  parts,  or  scales,  respecting  its  length,  one 
articulated  with  the  other:  the  first  of  those  scales  (cardo)  is  articu- 
lated with  the  common  base,  at  the  articulation  of  the  first  part  of 
the  tongue,  and  incloses  laterally  the  second  part  of  the  tongue, 
eoming  as  far  forwards  as  the  third  articulation:  on  the  end  of 
this  is  articulated  the  second  scale  (lobus),  which  continues  the 
hollow  groove  that  incloses  the  tongue  laterally;  this  terminates  in 
a point.  These  scales  have  some  hairs  on  their  edge. 

On  the  termination  of  the  second  part  is  placed  the.  true  tongue, 
having  two  lateral  portions  or  processes  on  each  side,  one  within 
the  other;  the  external  (palpus  labialis)  is  the  largest,  and  is  some- 
what similar  to  the  before-mentioned  scales.  This  is  composed  of 
four  parts,  or  rather  of  one  large  part,  on  which  three  smaller  are 
articulated,  having  motion  on  themselves.  The  first,  on  which  the 
others  stand,  is  articulated  at  the  edges  of  the  tongue,  on  the  basis 
or  termination  of  the  last-described  part  of  the  tongue ; this  has 
hairs  on  its  edge. 

A little  further  forwards  on  the  edges  of  the  tongue  are  tw'O  small 
thin  processes  (paraglossce),  so  small  as  hardly  to  be  seen  with  the 
naked  eye.  The  middle  part  of  all,  of  which  these  lateral  parts  are 
only  appendages,  is  the  true  tongue  (lingua).  It  is  something  longer 
than  any  of  the  before-mentioned  lateral  portions,  and  is  not  horny 
as  the  other  parts  are,  but  what  may  be  called  fleshy,  being  soft 
and  pliable.  It  is  composed  of  short  sections,  which  probably  are 
so  many  short  muscles,  as  in  fish,  for  they  are  capable  of  moving  it 
in  all  directions.  The  tongue  itself  is  extremely  villous,  having 
some  very  long  villi  at  the  point,  which  act,  I conceive,  somewhat 
like  capillary  tubes.* 

This  whole  apparatus  can  be  folded  up,  into  a very  small  corn- 

lip  of  the  ordinary  trophi.  I have  inserted  in  the  text  the  terms  by  which  the  dif- 
ferent parts  described  by  Hunter  are  known  to  entomologists.] 

* [Mr.  Kirby  observes,  “The  upper  part  of  this  tongue  is  cartilaginous,  and 
remarkable  for  a number  of  transverse  rings  : below  the  middle  it  consists  of  a 
membrane,  longitudinally  folded  in  inaction,  but  capable  of  being  distended  to  a 
considerable  size.  This  membranous  bag  receives  the  honey,  which  the  tongue, 
as  it  were,  laps  from  the  flowers,  and  conveys  it  to  the  pharynx. 


OBSERVATIONS  ON  BEES. 


447 


pass,  under  the  head  and  neck.  The  larynx  falls  back  into  the  neck, 
which  brings  the  extreme  end  of  the  first  portion  of  the  tongue 
within  the  upper  lip,  or  behind  the  two  teeth;  then  the  whole  of 
the  second  part,  which  consists  of  five  parts,  is  bent  down  upon 
and  under  this  first  part,  and  the  two  last  scales  are  also  bent 
down  over  the  whole,  so  that  the  true  tongue  is  inclosed  laterally 
by  the  two  second  horny  scales,  and  over  the  whole  lie  the  two 
first. 

The  oesophagus,  in  all  this  tribe  of  insects,  begins  just  at  the  root 
of  the  tongue,  as  in  other  animals,*  covered  anteriorly  by  a horny 
scale,  which  terminates  the  head,  and  which  may  be  called  the 
upper  lip  or  the  roof  of  the  mouth.  It  passes  down  through  the 
neck  and  thorax,  and  when  got  into  the  abdomen  it  immediately 
dilates  into  a fine  transparent  bag,  which  is  the  immediate  receiver 
of  whatever  is  swallowed.  From  this  the  food  (whatever  it  be)  is 
either  carried  further  on  into  the  stomach  to  be  digested,  or  is  re- 
gurgitated for  other  purposes.  To  ascertain  this  in  some  degree 
in  living  bees,  I caught  them  going  out  early  in  the  morning,  and 
found  this  bag  quite  empty:  some  time  after  I caught  others  return- 
ing home  and  found  the  bag  quite  full  of  honey,  and  some  of  it  had 
got  into  the  stomach.  Now  I suppose  that  which  was  in  the  craw 
was  for  the  purpose  of  regurgitation,  and  as  probably  they  had  fasted 
during  the  night,  part  had  gone  on  further  for  digestion.  What- 
ever time  the  contents  of  this  reservoir  may  be  retained,  we  never 
find  them  altered,  so  as  to  give  the  idea  of  digestion  having  taken 
place:  it  is  pure  honey.  From  this  bag  the  contents  can  be  moved 
either  way;  either  downwards  to  the  stomacli,  for  the  immediate 
use  of  the  animal  itself,  or  back  again,  to  be  thrown  out  as  store  for 
future  aliment. 

The  stomach  arises  from  the  lower  end  and  a little  on  the  right  side 
of  this  bag.  It  does  not  gradually  contract  into  a stomach,  nor  is  the 
outlet  a passage  directly  out,  but  in  the  centre  of  a projection  which 
enter  some  way  into  the  reservoir,  being  rather  an  inverted  pylorus, 
thickest  at  its  most  projecting  part,  with  a very  small  opening  in  the 
centre,  of  a peculiar  construction.  This  inward  projecting  partis 
easily  seen  through  the  coats  of  the  reservoir,  especially  if  full  of 
honey. 

The  stomach  begins  im  mediately  on  the  outside  of  the  reservoir,  and 
the  same  part  which  projects  into  the  reservoir  is  continued  some  way 
into  the  stomach,  but  appears  to  have  no  particular  construction  at  this 
end,  and  therefore  it  is  only  fitted  to  prevent  regurgitation  into  the  re- 

* This  observation  appears  to  have  been  overlooked  by  entomologists,  who 
continued  to  believe  that  the  opening  of  the  pharynx  was  situated  below  the  pro- 
boscis in  bees,  until  the  researches  of  Savigny  on  the  oral  organs  of  these  insects 
and  of  the  Lepidoptera  were  made  public.  Cuvier,  in  his  Analyse  des  Travaux 
de  la  Classe  des  Sciences  Mathematiques  el  Physiques  de  I'  Institut,  'pendant  /’  Annie 
1814,  observes,  “On  avail  cm  voir  que  I’ouverture  du  pharynx  etait  situee  en 
dessous  de  cette  trompe  ou  de  cette  levre,  tandis  que  dans  les  masticateurs  ordi- 
naires  elle  I’est  en  dessous ; mais  c’  etait  une  erreur ; le  pharynx  est  toujours  sur 
la  base  de  la  trompe,  et  il  y est  meme  garnis  de  parties  interessantes  a reconnaitre, 
et  dont  M.  Savigny  donne  une  description  detaillee.  ” p.  25.] 


448 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


servoir,  as  such  would  spoil  the  honey.  This  construction  of  parts  is 
well  adapted  for  the  purpose,  for  the  end  projecting  into  the  reservoir 
preventsany  honeyfrom  gettingintothe  stomach,  because  it  acts  there 
as  a valve  ; therefore  whatever  is  taken  in  must  be  by  an  action  of  this 
valvular  part.  The  stomach  has  a good  deal  the  appearance  of  a gut, 
especially  as  it  seems  to  come  out  from  a bag.  It  passes  almost  di- 
rectly downwards  in  the  middle  of  the  abdomen.  Its  inner  surface  is 
very  much  increased,  by  having  either  circular  valves,  somewhat  like 
the  valvulse  conniventesin  the  human  jejunum,  or  spiral  folds,  as  in  the 
intestine  of  the  shark,  &c. ; these  may  be  seen  through  the  external 
coats.  In  this  part  the  food  undergoes  the  change.  Where  the  sto- 
mach terminates  is  not  exactly  to  be  ascertained, ^but  it  soon  begins  to 
throw  itself  into  convolutions  and  becomes  smaller. 

The  intestine  makes  two  or  three  twists  upon  itself,  in  which  part 
it  is  enveloped  in  the  ducts,  constituting  the  liver  and  probably  the 
pancreas,  and  at  last  passes  on  straight  to  the  termination  of  the 
abdomen.  Here  it  is  capable  of  becoming  very  large,  to  serve  upon 
occasion  as  a reservoir,  containing  a large  quantity  of  excrement; 
it  then  contracts  a little,  and  opens  under  the  posterior  edge  of  the 
last  scale  of  the  back,  above  the  sting  in  the  female  and  labourers, 
and  the  penis  in  the  male.* 

Of  the  Sense  of  Bees. 

Bees  certainly  have  the  five  senses.  Sight  none  can  doubt.  Feel- 
ing they  also  have;  and  there  is  every  reason  for  supposing  they 
have  likewise  taste,  smell,  and  hearing.  Taste  we  cannot  doubt; 
but  of  smell  we  may  not  have  such  proofs  ; yet,  from  observation,  I 
think  they  give  strong  signs  of  smell.  When  bees  are  hungry,  as  a 
young  swarm  in  wet  weather,  and  arc  in  a glass  hive,  so  that  they 
can  be  examined,  if  we  put  some  honey  into  the  bottom  it  will  imme- 
diately breed  a commotion;  they  all  seem  to  be  upon  the  scent; 
even  if  they  are  weak  and  hardly  able  to  crawl,  they  will  throw 
out  their  proboscides  as  far  as  possible  to  get  to  it,  although  the  light 
is  very  faint.  This  last  appears  to  arise  more  from  smell  than  see- 
ing. If  some  bees  are  let  loose  in  a bee-hive,  and  do  not  know  from 
which  house  they  came,  they  will  take  their  stand  upon  the  outside 
of  some  hive  or  hives,  especially  when  the  evening  is  coming  on; 
whether  this  arises  from  the  smell  of  the  hives  or  sound  I can  hardly 
judge. 

Of  the  Voice  of  Bees. 

Bees  may  be  said  to  have  a voice.  They  are  certainly  capable  of 
forming  several  sounds.  They  give  a sound  when  flying,  which 
they  can  vary  according  to  circumstances.  One  accustomed  to 
bees  can  immediately  tell  when  a bee  makes  an  attack  by  the  sound. 

* [See  Preps.  476,  477,  601,  602,  603,  604,  605.  Physiological  Series,  Hun- 
terian Museum.] 


OBSERVATIONS  ON  BEES. 


449 


These  are  probably  made  by  the  wings.  They  may  be  seen  stand- 
ing at  the  door  of  their  hive,  with  the  belly  rather  raised,  and, 
moving  their  wings,  making  a noise.  But  they  produce  a noise 
independent  of  their  wings  ; for  if  a bee  is  smeared  all  over  with 
honey,  so  as  to  make  the  wings  stick  together,  it  will  be  found  to 
make  a noise  which  is  shrill  and  peevish.  To  ascertain  this  further, 
I held  a bee  by  the  legs  with  a pair  of  pincers,  and  observed  it  then 
made  the  peevish  noise,  although  the  wings  were  perfectly  still : I 
then  cut  the  wings  off,  and  found  it  made  the  same  noise.  I ex- 
amined it  in  water,  but  it  then  did  not  produce  the  noise  till  it  was 
very  much  teased,  and  then  it  made  the  same  kind  of  noise,  and  I 
could  observe  the  water,  or  rather  the  surface  of  contact  of  the 
water,  with  the  air  at  the  mouth  of  an  air-hole  at  the  root  of  the 
wing,  vibrating.  I have  observed  that  they,  or  some  of  them, 
make  a noise  the  evenings  before  they  swarm,  which  is  a kind  of 
ring,  or  sound  of  a small  trumpet:  by  comparing  it  with  the  notes 
of  the  piano-forte,  it  seemed  to  be  the  same  with  the  lower  A of 
the  treble. 

Of  the  Female  Parts. 

I may  here  observe  that  insects  differ  from  most  of  the  classes  of 
animals  above  them  in  having  their  eggs  formed  in  the  ducts  along 
which  they  pass,  not  in  a cluster  on  the  back,  as  in  some  fish  (for 
instance,  all  of  the  ray  kind,  or  what  are  called  the  amphibia),  in 
the  bird,  and  as  is  supposed  in  the  quadruped  ;*  from  thence  the 
eggs  are  taken  up,  and  by  the  ducts  are  carried  along  to  their 
'places  of  destination. 

Of  the  Oviducts. 

The  female  of  the  common  bee,  similar  to  all  the  females  of  the 
bee  tribe,  has  six  oviducts  on  each  side,  beginning  by  very  small 
and  almost  imperceptible  threads,  as  high  as  the  chest;  they  then 
form  one  cord  coiled  up,  or  pass  very  serpentine,  and  become 
larger  and  larger  as  they  approach  the  anus,  owing  to  the  gradual 
increased  size  of  the  eggs  in  them,  which  are  now  more  distinct, 
and  give  the  duct  a sort  of  interrupted  appearance  toward  the  lower 
end.  The  six  ducts,  when  full  of  eggs,  make  a kind  of  quadrangle, 
then  all  unite  into  one  duct,  which  enters  the  duct  common  to  it 
and  the  oviducts  of  the  other  side.  The  ducts  common  to  the  six 
oviducts  on  each  side  are  extremely  tender,  so  much  so  that  it  is  dif- 
ficult to  save  them.  The  duct  common  to  those  on  both  sides  may 
be  called  the  vagina,  and  it  is  continued  to  the  anus  or  termination 
of  the  belly. 

Of  the  Male  Parts. 

The  male  parts  of  generation  in  the  common  bee  are  much  larger 

* [This  supposition,  that  the  ova  of  the  mammalia  are  formed  in  the  ovaria,  i,  e. 
in  a cluster  attached  to  the  dorsal  aspect  of  the  abdomen,  and  not  in  the  ducts 
along  which  they  pass,  is  now  proved  incontestably  by  the  researches  of  V.  Baer 
and  other  physiologists.] 


39* 


450 


HUNTER  ON  THE  ANIMAL  CCCONOMY. 


than  in  the  humble  bee.  This  we  suppose  necessary,  considering 
the  vast  number  of  eggs  the  common  bee  lays  more  than  the  hum- 
ble bee  does. 

The  external  parts  of  generation  of  the  male  bee  are  rather  more 
under  the  belly  than  in  the  others  of  this  tribe,  not  so  much  at  the 
termination  of  the  belly,  and  they  are  rather  more  exposed,  the  two 
last  scales,  especially  the  under  one,  not  projecting  so  much  ; the 
two  holders  are  not  so  projecting  beyond  their  base,  nor  are  they 
so  hooked  or  sharp  as  in  the  humble  bee  ; hardly  deserving  the 
name  of  holders.  From  the  external  parts  passes  up  into  the  abdo- 
men a pretty  large  sheath,  whose  termination  incloses  the  glans 
penis.  It  is  a bulbous  part,  having  a dark-coloured  horny  part 
upon  it,  which  has  two  processes  near  its  opening  externally,  one  on 
each  side,  of  a yellow  colour  ; it  has  another  process,  which  is  white, 
and  seems  to  be  a gland.  It  can  be  made  to  pass  along  this  sheath 
or  prepuce,  and  appear  externally  : I have  been  able,  with  a pair  of 
forceps,  to  invert  the  sheath,  beginning  externally  at  the  mouth,  and 
pulling  out  a little  at  a time,  by  shifting  my  hold,  till  the  glands  has 
appeared  externally. 

The  internal  parts  are  the  testicles,  with  their  appendages.  The 
testicles  are  two  small  oblong  bodies,  lying  near  the  back,  having 
a vast  number  of  air  vessels,  passing  into  them,  and  ramifying  upon 
them.  They  are  of  a pale  yellowish  colour.  From  their  lower 
ends  pass  down  ducts,  which  may  be  called  vasa  deferentia,  and 
which  enter  two  bags:  these  two  bags,  into  which  the  vasa  defer- 
entia enter,  are  pi’obably  reservoirs  for  the  semen.  From  the  union, 
of  these  two  bags  passes  out  a duct,  which  runs  towards  the  ter- 
mination of  the  abdomen,  and  ends  in  the  penis.  These  three  parts, 
namely,  testicles  with  their  ducts,  the  two  bags,  and  the  duct  arising 
from  them,  which  I have  termed  urethra,  are  all  folded  on  each 
other,  so  as  to  appear  as  one  body. 

In  the  introduction  to  this  account  of  bees  I observed,  that  several 
things  in  their  oeconomy  might  escape  us  if  we  considered  them 
alone,  but  might  be  made  out  in  other  insects:  an  instance  of  this 
occurs  in  the  impregnation  of  the  female  bee.  The  death  of  the 
males  in  the  month  of  August,  so  that  not  one  is  left,  and  yet  the 
queen  to  breed  in  the  month  of  March,  must  puzzle  any  one  not 
acquainted  with  the  mode  of  impregnation  of  the  females  of  most 
insects.  Insects,  respecting  the  males,  are  of  two  kinds  : one, 
where  the  male  lives  through  the  winter,  as  well  as  the  females; 
and  the  other,  where  every  male  of  that  species  dies  before  the 
winter  comes  on  ; among  which  may  be  considered,  as  a third,  those 
where  both  male  and  female  die  the  same  year.  Of  the  first,  I shall 
only  give  the  common  fly  as  an  instance  ; of  the  second,  I shall  just 
mention  all  of  the  bee  tribe;  and  the  third  maybe  illustrated  in 
the  silk-worm  moth.  The  mode  of  impregnation  in  the  first  is  its 
being  continued  uninterruptedly  through  the  whole  period  of  laying 
eggs ; W'hile  in  the  second,  the  copulation  is  in  store ; and  in  the 
third  the  female  lays  up,  by  the  copulation,  a store  of  semen,  al- 


OBSERVATIONS  ON  BEES. 


451 


though  the  male  is  alive.  Of  this  I shall  now  give  an  explanation 
in  the  silk-moth,  which  may  be  applied  to  the  bee,  and  many  other 
insects. 

In  dissecting  the  female  parts  in  the  silk-moth,  I discovered  a 
bag  lying  on  what  may  be  called  the  vagina,  or  common  oviduct, 
whose  mouth  or  opening  was  external,  but  it  had  a canal  of  com- 
munication between  it  and  the  common  oviduct.  In  dissecting 
these  parts  before  copulation  I found  this  bag  empty,  and  when  I 
dissected  them  after,  I found  it  full.  Suspecting  this  to  contain  the 
semen  of  the  male,  I immediately  conceived  the  following  experi- 
ment. I opened  the  female  as  soon  as  the  male  had  united  to  her, 
and  found  the  penis  in  the  opening  of  this  bag,  and  by  opening  the 
duct  where  the  penis  lay  I observed  the  semen  lying  on  the  end 
of  the  penis.  In  another,  I observed  the  bag  to  fill  in  the  time  of 
copulation ; and  in  a pair  that  died  in  the  act,  I found  the  penis  in 
this  passage. 

When  we  consider  the  impregnation  of  the  egg  in  the  silk-worm, 
we  may  observe  the  following  circumstances: 

First,  many  of  the  ova  are  completely  formed,  and  covered  with 
a hard  shell,  before  copulation ; secondly,  the  animals  are  a vast 
while  in  the  act  of  copulation ; and,  thirdly,  the  bags  at  the  anus 
are  filled  during  the  time  of  copulation.  From  the  first  observation 
it  appears  that  the  egg  can  receive  the  male  influence  through  the 
hard  or  horny  part  of  the  shell.  To  know  how  far  the  whole,  or 
only  a part  of  the  eggs,  were  impregnated  by  each  copulation,  I 
made  the  following  experim.ents.'*  I took  a female  just  emerged 
out  of  her  cell,  and  put  a male  to  her,  and  allowmd  them  to  be  connect- 
ed their  full  time.  They  were  in  copulation  ten  hours.  I then  put 
her  into  a box  by  herself,  and  when  she  laid  her  eggs,  I numbered 
the  different  parcels  as  she  laid  them,  viz.,  1,  2,  3,  4,  5 ; these  eggs 
I preserved,  and  in  the  summer  following  I perceived  that  the  No. 
5 was  as  prolific  as  the  No.  1 ; so  that  this  one  copulation  was 
capable  of  impregnating  the  whole  brood  ; and  therefore  the  male 
influence  must  go  either  along  the  oviduct  its  whole  length,  and  im- 
pregnate the  incomplete  eggs  as  well  as  the  complete,  which  ap- 
pears to  be  not  likely,  or  those  not  yet  formed  were  impregnated 
from  the  reservoir  in  the  act  of  laying:  for  I conceived  that  these 
bags,  by  containing,  semen,  had  a power  of  impregnating  the  egg  as 
it  passed  along  to  the  anus,  just  as  it  traversed  the  mouth  of  the  duct 
of  communication. 

Finding  that  eggs  completely  formed  could  be  impregnated  by 
the  semen,  and  also  finding  that  the  before-mentioned  bag  was  a re- 
servoir for  the  se.men  till  wanted,  I wished  next  to  discover  if  they 
could  be  impregnated  from  the  semen  of  this  bag;  but  as  this  must 
be  done  without  the  act  of  copulation,  I conceived  it  proper,  first,  to 
see  whether  the  ova  of  insects  might  be  impregnated  without  the 
natural  act  of  copulation,  by  applying  the  male  semen  over  the  ova, 

* All  these  experiments  on  the  silk-moth  vrere  begun  in  the  summer  1767,  and 
repeated  by  Mr.  Bell  in  the  year  1770. 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


4r»2 

just  as  they  were  laid.  The  following  experiments  were  made  on 
the  silk-moth. 

Experiment  I.  I took  a female  moth,  as  soon  as  she  escaped 
from  her  pod,  and  kept  her  carefully  by  herself  upon  a clean  card, 
till  she  began  to  lay  ; then  I took  males  that  were  ready  for  copula- 
tion, opened  them,  exposing  their  seminal  ducts,  and  after  cutting 
into  these,  collected  their  semen  with  a hair  pencil : with  this  semen 
I covered  the  ova,  as  soon  as  they  passed  out  of  the  vagina.  The 
card  with  these  eggs,  having  a written  account  of  the  experiment 
upon  it,  I kept  in  a box  by  itself.  In  the  ensuing  season  eight  of 
the  ova  hatched  at  the  same  time  with  others  naturally  impreg- 
nated. Thus  then  I ascertained  that  the  eggs  could  be  impregnated 
by  art,  after  they  were  laid.* 

The  ova  laid  by  females  that  had  not  been  impregnated  did  not 
stick  where  they  were  laid  ; so  that  the  semen  would  appear  not 
only  to  impregnate  the  ova,  but  also  to  be  the  means  of  attaching 
them. 

To  know  whether  that  bag  in  the  female  silk-moth  which  increased 
at  the  time  of  copulation,  was  filled  with  the  semen  of  the  male, 
I made  the  following  experiment. 

Experiment  II.  I took  a female  moth,  as  soon  as  she  had  escaped 
from  the  pod,  and  kept  her  on  a card  till  she  began  to  lay.  I then 
took  females  that  were  fully  impregnated  before  they  began  to  lay, 
and  dissected  out  that  bag  which  I supposed  to  be  the  receptacle 
for  the  male  semen  ; and  wetting  a camel-hair  pencil  with  this  mat- 
ter, covered  the  ova  as  soon  as  they  passed  out  of  the  vagina. 
These  ova  were  laid  carefully  on  the  clean  card,  and  kept  till  the 
ensuing  season,  when  they  all  hatched  at  the  same  time  with  those 
naturally  impregnated. 

This  proves  that  this  bag  is  the  receptacle  for  the  semen,  and 
gradually  decreases  as  the  eggs  are  laid. 

Of  the  Sting  of  the  Bee. 

I have  observed  that  it  is  only  the  queen  and  the  labourers  that 
have  stings  ; and  this  provision  of  a sting  is  perhaps  as  curious  a 
circumstance  as  any  attending  the  bee,  and  probably  is  one  of  the 
characters  of  the  bee  tribe. 

The  apparatus  itself  is  of  a very  curious  construction,  fitted  for  in- 
flicting a wound,  and  at  the  same  time  conveying  a poison  into  that 
wound.  The  apparatus  consists  of  two  piercers,  conducted  in  a 
groove,  or  director,  which  appears  to  be  itself  the  sting.  This 
groove  is  somewhat  thick  at  its  base,  but  terminates  in  a point ; it 
is  articulated  to  the  last  scale  of  the  upper  side  of  the  abdomen  by 
thirteen  thin  scales,  six  on  each  side,  and  one  behind  the  rectum. 
These  scales  inclose,  as  it  were,  the  rectum  or  anus  all  round  ; 
they  can  hardly  be  said  to  be  articulated  to  each  other,  only  at- 

* [This  circumstance  was  proved,  as  regards  the  ova  of  fishes,  by  Gleditsch. 
See  M^moires  de  I’Acad.  de  Berlin,  1764.] 


OBSERVATIONS  ON  BEES. 


453 


tached  by  thin  membranes,  which  allow  of  a variety  of  motions ; 
three  of  them,  however,  are  attached  more  closely  to  a round  and 
curved  process,  which  comes  from  the  basis  of  the  groove  in  which 
the  sting  lies,  as  also  to  the  curved  arms  of  the  sting,  wdiich  spread 
out  externally.  The  two  stings  may  be  said  to  begin  by  those  two 
curved  processes  at  their  union  with  the  scales,  and  converging 
towards  the  groove  at  its  base,  which  they  enter,  then  pass  along  it 
to  its  point.  They  are  serrated  on  their  outer  edges,  near  to  the 
point.  These  two  strings  can  be  thrust  out  beyond  the  groove 
although  not  far,  and  they  can  be  drawn  within  it ; and,  I believe, 
can  be  moved  singly.  All  these  parts  are  moved  by  muscles,  which 
we  may  suppose  are  very  strong  in  them,  mucli  stronger  than  in 
other  animals  ; and  these  musclesgive  motion  in  almost  all  directions, 
but  more  particularly  outwards.  It  is  wonderful  how  deep  they 
will  pierce  solid  bodies  with  the  sting.  I have  examined  the  length 
they  have  pierced  the  palm  of  the  hand,  which  is  covered  with  a 
thick  cuticle  : it  has  often  been  about  the  ^^th  of  an  inch.  To  per- 
form this  by  mere  force  two  things  are  necessary,  power  of  muscles 
and  strength  of  the  sting,  neither  of  which  they  seem  to  possess  in 
sufficient  degree.  I own  I do  not  understand  this  operation.  I 
am  apt  to  conceive  there  is  something  in  it  distinct  from  simple 
force  applied  to  one  end  of  a body  ; for  if  this  was  simply  the  case, 
the  sting  of  the  bee  could  not  be  made  to  pierce  by  any  power 
applied  to  its  base,  as  the  least  pressure  bends  it  in  any  direction  ; 
it  is  possible  the  sen'ated  edges  may  assist  by  cutting  their  way  in, 
like  a saw. 

The  apparatus  for  the  poison  consists  of  two  small  ducts,  which 
are  the  glands  that  secrete  the  poison  : these  two  lie  in  the  abdomen, 
among  the  air-cells,  cSic. : they  both  unite  into  one,  w'hich  soon  enters 
into,  or  forms,  an  oblong  bag,  like  a bladder  of  urine ; at  the  oppo- 
site end  of  which  passes  out  a duct,  wdtich  runs  tow'ards  the  angle 
where  the  two  stings  meet ; and  entering  between  the  two  stings, 
is  continued  between  them  in  a groove,  which  forms  a canal  by  the 
union  of  the  two  stings  to  this  point.  There  is  another  duct  on  the 
right  of  that  described  above,  which  is  not  so  circumscribed,  and 
contains  a thicker  matter,  which,  as  far  as  I have  been  able  to  judge, 
enters  along  with  the  other:  but  it  is  the  first  that  contains  the  poi- 
son, which  is  a thin,  clear  fluid.  To  ascertain  wdiich  was  the 
poison,  I dipped  points  of  needles  into  both,  and  pricked  the  back 
of  the  hand  : and  those  punctures  that  had  the  fluid  from  the  first- 
described  bags  in  them  grew  sore  and  inflamed,  while  the  others 
did  not.  From  the  stings  having  serrated  edges,  it  is  seldom  the 
bees  can  disengage  them;  and  they  immediately  upon  stinging 
endeavour  to  make  their  escape,  but  are  generally  prevented,  as  it 
were  caught  in  their  own  trap;  and  the  force  they  use  commonly 
drags  out  the  whole  of  the  apparatus  for  stinging,  and  also  part  of 
the  bowels;  so  that  the  bee  most  frequently  falls  a sacrifice  imme- 
diately upon  having  effected  its  purpose.  Upon  a superficial  view 
one  conceives  that  the  first  intention  of  the  bee  having  a sting  is 


454 


HUNTER  ON  THE  ANIMAL  CEUONOMY. 


evident;  one  sees  it  has  property  to  defend,  and  that  therefore  it  is 
fitted  for  defence  : but  why  it  should  naturally  fall  a sacrifice  in  its 
own  defence,  does  not  so  readily  appear : besides,  all  bees  have  stings, 
although  all  bees  have  not  property  to  defend,  and  therefore  are 
not  under  the  same  necessity  of  being  so  provided.  Probably  its 
having  a sting  to  use  was  sufficient  for  nature  to  defend  the  bee 
without  using  it  liberally  ; and  the  loss  of  a bee  or  two,  when  they 
did  sting,  was  of  no  consequence:  for  it  is  seldom  that  more  die. 

I have  now  carried  the  operations  of  a hive,  or  the  oeconomy  of 
the  bee,  completely  round  the  year  ; in  which  time  they  revolve  to 
the  first  point  we  set  out  at,  and  the  continuance  is  only  a repetition 
of  the  same  revolutions  as  I have  now  described:  but  those  revo- 
lutions occasion  a series  of  effects  in  the  comb,  which  effects  in 
time  produce  variations  in  the  life  of  the  hive.  Besides,  there  are 
observations  that  have  little  to  do  with  the  ceconomy  of  a year,  but 
include  the  whole  of  the  life  of  this  insect,  or  at  least  its  hive. 

Of  the  Life  of  the  Bee. 

I have  observed  that  the  life  of  the  male  is  only  one  summer,  or 
rather  a month  or  two  ; and  this  we  know  from  there  being  none 
in  the  winter,  otherwise  their  age  could  not  be  ascertained,  as  it  is 
impossible  to  learn  the  age  of  either  the  queen  or  labourers.  Some 
suppose  that  it  is  the  young  bees  which  swarm  ; and  most  probably 
it  is  so  : but  I think  it  is  probable  also,  that  a certain  number  of 
young  ones  may  be  retained  to  keep  up  the  stock,  as  we  must  sup- 
pose that  many  of  the  old  ones  are,  from  accidents  of  various  kinds, 
lost  to  the  hive;  and  we  could  conceive,  that  a hive  three  or  four 
years  old  might  not  have  an  original  bee  in  it,  although  a bee 
might  live  twice  that  time.  But  there  must  be  a period  for  a bee 
to  live  ; and  if  I were  to  judge  from  analogy,  I should  say  that  a 
bee’s  natural  life  is  limited  to  a certain  number  of  seasons;  viz., 
one  bee  does  not  live  one  year,  another  two,  another  three,  &c.  I 
even  conceive  that  no  individual  insect  of  any  species  lives  one 
month  longer  than  the  others  of  the  same  species.  I believe  this 
is  the  case  with  all  insects  ; but  the  age  of  either  a labourer  or  a 
queen  may  never  be  discovered.  One  might  suppose  that  the  life 
of  a bee,  and  the  time  a hive  can  possibly  last,  would  be  nearly 
equal:  although  this  is  not  absolutely  necessary,  because  they  can 
produce  a succession,  which  they  probably  do;  for  I am  very  ready 
to  imagine,  that  after  the  first  brood  in  the  season,  all  the  last  winter 
bees  die,  and  the  hive  is  occupied  with  the  first  brood  ; and  that 
they  breed  the  first  swarm,  or  that  the  old  breed  the  whole  of  this 
season’s  breeding,  and  then  die,  and  those  that  continue  through 
the  winter  are  the  young,  and  if  so,  then  they  follow  the  same 
course  with  their  progenitors. 

The  comb  of  a hive  may  be  said  to  be  the  furniture  and  store- 
house of  the  bees,  which  by  use  wear  out ; and  from  the  descrip- 
tion I have  given,  it  will  appear  that  the  comb  in  time  will  be 
rendered  unfit  for  use.  I observed  that  they  did  not  clean  out  the 


OBSERVATIONS  ON  BEES. 


455 


excrement  of  the  maggot,  and  that  the  maggot,  before  it  moved 
into  the  chrysalis  state,  lined  the  cell  with  a silk,  similar  to  many 
other  insects.  It  lines  the  whole  cell,  top,  sides,  and  bottom  : the 
two  last  are  permanent ; and  at  the  bottom  it  covers  with  this  lining 
its  own  excrement. Why  the  bee  maggot  is  formed  to  do  this  is 
probably  because  honey  afterwards  is  to  be  put  into  the  cell ; so 
that  the  honey  is  laid  into  this  last  silken  bag.  How'  often  they 
may  breed  in  the  same  cell  I do  not  know,  but  I have  known  them 
three  times  in  the  same  season;  each  time  the  excrement  has  been 
•accumulating,  and  the  cell  has  been  lined  three  times  with  silk. 
From  this  account  we  must  see  that  a cell  in  time  will  be  so  far 
filled  up  as  to  render  it  unfit  for  breeding.  On  separating  the 
lining  of  silk,  which  is  easiest  done  at  the  bottom,  on  account  of  the 
dried  excrement  between  each  lining,  I have  counted  above  twenty 
different  linings  in  one  cell,  and  found  the  cell  about  one-quarter,  or 
one-third  filled  up  ; when  such  a cell,  or  a piece  of  comb  wdth  such 
cells,  is  steeped  in  water,  so  as  to  soften  the  excrement  between 
the  linings,  they  are  separated  from  each  other  at  the  bottom  by 
the  swelling  of  the  excrement,  so  that  they  can  be  easily  counted. 
A piece  of  comb  so  circumstanced,  when  boiled  for  the  wax,  will 
keep  its  form,  and  the  small  quantity  of  wax  is  squeezed  out  of 
different  parts  as  if  squeezed  out  of  a sponge,  and  runs  together 
into  the  crevices  ; while  a piece  of  comb,  that  never  has  been  bred 
in,  even  of  the  same  hive,  melts  almost  wholly  dowm.  It  is  this 
wax  that  has  the  fine  yellow,  while  the  other  of  the  same  hives, 
although  brown,  yet  shall  be  white  when  melted ; so  that  I w'as 
led  to  imagine  the  wax  took  its  tinge  from  the  farina,  excrement, 
&c.,  but  upon  boiling  pure  wax  with  such  materials  it  was  not 
tinged  wdth  this  transparent  yellowy  only  became  dirty.  In  some 
of  those  cells  that  had  probably  been  bred  in  twenty  times  or  more, 
W'hen  soaked  so  as  to  make  the  excrement  swell,  I have  seen  the 
bottom  of  the  last  lining  rise  even  with  the  mouth,  or  top  of  the 
cell,  so  that  the  cavity  of  the  cell  was  now  full : in  others,  I have 
seen  it  rise  higher  than  the  mouth,  so  that  the  last-formed  layers 
were  almost  inverted,  and  turned  inside  out.  A piece  of  such  comb, 
consisting  of  two  rows  of  cells,  is  to  be  considered  as  a mould,  and 
the  lining  of  silk  and  the  excrement  as  the  cast;  when  this  is  boiled, 
so  as  either  to  extract  all  the  wax  or  mould,  or  to  destroy  its  origi- 
nal regular  formation  which  constituted  the  comb,  and  nothing  is 
left  but  the  cells  of  silk,  &c.,  they  all  easily  separate  from  each 
other,  being  only  so  many  casts,  wnth  the  mould  destroyed;  and 
the  bottoms,  which  were  indented  into  each  other,  are  very  perfect. 

From  the  above  account  we  must  see  that  the  combs  of  a hive 
can  only  last  a certain  number  of  years  ; however,  to  make  them 
last  longer,  the  bees  often  add  a little  to  the  mouth  of  the  cell,  which 
is  seldom  done  with  wax  alone,  but  with  a mixture;  and  they  some- 
times cover  the  silk  lining  of  the  last  chrysalis  ; but  all  this  makes 
such  cells  clumsy,  in  comparison  to  the  original  ones. 

* This  neither  the  wasp  nor  the  hornet  do,  although  they  do  not  clean  out  the 
excrement  of  their  maggots. 


456 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


40.  ANATOMICAL  REMARKS  ON  A NEW  MARINE 
ANIMAL.* 

Animals  which  come  from  foreign  conntries,  and  cannot  be 
brought  to  England  alive,  must  be  kept  in  spirits  to  preserve  them 
from  putrefaction,  which  makes  them  less  fitted  for  anatomical  ex- 
amination ; for  the  spirits  which  preserve  them  produce  a change 
in  many  of  their  properties,  and  alter  the  natural  colours  and  texture 
of  their  parts,  so  that  often  the  structure  alone  of  the  animal  can  be 
ascertained;  and  where  this  is  not  naturally  distinct  it  becomes 
frequently  entirely  obscured,  and  the  texture  of  the  finer  parts  is 
wholly  destroyed,  requiring  a very  extensive  knowledge  of  such 
parts  in  animals  at  large,  to  assist  us  in  bringing  them  to  light ; this 
happens  to  be  the  case  with  the  animal  whose  dissection  is  the  sub- 
ject of  this  postscript. 

The  animal  may  be  said  to  consist  of  a fleshy  covering,  a 
stomach  and  intestinal  canal,  and  the  two  cones  with  their  ten- 
tacula  and  moveable  shell,  which  last  may  be  considered  as 
appendages. 

The  body  of  the  animal  is  flattened,  and  terminates  in  two  edges, 
wdiich  are  intersected  by  rugae,  the  fasciculi  of  transverse  muscular 
fibres  which  run  across  the  back  being  continued  over  them.  Upon 
each  of  these  edges  is  placed  a row'  of  fine  hairs,  which  project  to 
some  distance  from  the  skin. 

The  fleshy  covering  consists  principally  of  muscular  fibres : those 
upon  the  back  are  placed  transversely,  to  contract  the  body  later- 
ally ; those  on  the  belly  longitudinally,  to  shorten  the  animal  when 
stretched  out,  and  to  draw  it  into  the  shell. 

The  stomach  and  intestine  make  one  straight  canal:  the  anterior 
end  of  this  forms  the  mouth,  which  opens  into  the  grooves  made 
by  the  spiral  turns  of  the  tentacula  round  the  stem  of  each  of 
the  cones  ; and  the  intestine  at  the  posterior  end  opens  externally, 
forming  the  anus.  From  tlie  contracted  state  of  the  animal  the 
intestine  is  thrown  into  a number  of  folds. 

On  examining  the  cones  and  the  tentacula  I at  first  believed  that 
the  spiral  form  arose  from  their  being  in  a contracted  state;  and 
that  when  the  tentacula  were  erected  the  cone  untwisted,  forming 
a longer  cone  with  the  tentacula  arising  from  its  sides,  like  the  plume 

* [This  animal  was  sent  to  Mr.  Hunter  from  Barbadoesby  Sir  Everard  (then 
Mr.)  Home,  who  described  it  in  the  Philosophical  Transactions  for  1784  as  a 
species  of  Jlctinia,  and  the  anatomical  remarks  in  the  text  from  the  postscript 
to  that  Paper.  The  same  species  had  been,  however,  previously  described  and 
figured  by  Pallas  in  the  Miscellanea  Zoologica,  p.  139,  tab.  x.  fig.  2 — 10,  (17G6,) 
and  had  been  more  correctly  referred  by  that  distinguished  naturalist  to  the  genus 
Serpula,  under  the  name  of  Serpula  gigantea.  It  still  retains  this  denomination, 
and  is  placed  among  the  tubicular  Anellides  in  the  latest  edition  of  the  Regne 
■Animal  of  Cuvier.] 


ANATOMICAL  REMARKS,  ETC. 


457 


from  the  stem  of  a feather ; and  that  this  stem  was  drawn  in  or 
shortened  by  means  of  a muscle  passing  along  the  centre,  which 
threw  the  tentacula  into  a spiral  line,  similar  to  the  penises  of  many 
birds ; but  how  far  this  is  really  the  case  I have  not  been  able  to 
ascertain. 

The  internal  structure  of  this  animal,  like  most  of  those  which 
have  tentacula,  is  very  simple ; it  differs,  however,  materially  from 
many,  in  having  an  anus,  most  animals  of  this  tribe,  as  the  polypi, 
having  only  one  opening,  by  which  the  food  is  received,  and  the 
excrementitious  part  of  it  also  afterwards  thrown  out.^  This  we 
might  have  supposed,  from  analogy,  to  take  place  in  the  animal 
which  is  here  described,  more  particularly  since  it  is  inclosed  in  a 
hard  shell,  at  the  bottom  of  which  there  appears  to  be  no  outlet ; 
but  as  there  is  an  anus  this  cannot  be  the  case. 

It  is  very  singular  that  in  the  leech,f  polypi,  &c.,  where  no 
apparent  inconvenience  can  arise  from  having  an  anus,  there  is  not 
one  ; while  in  this  animal,  where  it  would  seem  to  be  attended  with 
many,  we  find  one  ; but  there  being  no  anus  in  the  polypi,  &c.,  may 
depend  upon  some  circumstance  in  the  animal  oeconomy  which  we 
are  at  present  not  fully  acquainted  with. 

The  univalves,  whose  bodies  are  under  similar  circumstances 
respecting  the  shell  with  this  animal,  have  the  intestine  reflected 
back,  and  the  anus  by  that  means  brought  near  to  the  external 
opening  of  the  shell,  the  more  readily  to  discharge  the  excrement ; 
and  although  this  structure  in  these  animals  appears  to  be  solely 
intended  to  answer  that  purpose,  yet  when  we  find  the  same  struc- 
ture in  the  black  snail,  which  has  no  shell,  this  reasoning  will  not 
wholly  apply,  and  we  must  refer  it  to  some  other  intention  in  the 
animal  osconomy.J 

In  this  animal  we  must  therefore  rest  satisfied  that  the  disadvan- 
tageous situation  of  the  anus,  with  respect  to  the  excrement’s  being 
discharged  from  the  shell,  answers  some  purpose  in  the  oeconomy 
of  the  animal  which  more  than  counterbalances  the  inconveniences 
produced  by  it. 

It  would  appear,  from  considering  all  the  circumstances,  that  the 
excrement  thrown  out  at  the  anus  must  pass  from  the  tail  along  the 
inside  of  the  tube,  between  it  and  the  body  of  the  animal,  till  it 
comes  to  the  external  opening  of  the  shell,  as  there  is  no  other 
evident  mode  of  discharging  it. 

How  the  tube  or  shell  is  formed  in  stone  or  coral  is  not  easily 
ascertained.  It  may  be  asked  whether  this  animal  has  the  power 
of  boring  backwards,  as  the  Teredo  navalis  probably  does,  or 

* [This  is  not  the  case  with  those  Polypi  which  have  the  tentacula  beset  with 
vibratile  cilia,  as  the  Flustrae,  Escharas,  Fescularias,  &c.,  as  in  these  there  is  a re- 
flected intestinal  canal,  terminating  by  a distinct  anus,  opening  near  the  mouth.] 

f [In  the  leech  the  alimentary  canal  terminates  by  a minute  anus,  situated 
above  the  caudal  sucker.] 

]:  [The  reflected  disposition  of  the  intestinal  canal  is,  in  a greater  or  less  de- 
gree, common  to  all  molluscous  animals,  and  the  anus  is  thus  brought  into  com- 
munication with  the  respiratory  cavity.] 

40 


458 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


whether  the  stone  or  coral  is  formed  at  the  same  time  with  the 
animal,  and  grows  and  increases  with  it  ; and  if  we  consider  all  the 
circumstances,  this  last  would  appear  to  be  most  probable,  and  agree 
best  with  the  different  phaenomena;  for  the  coral  is  lined  with  a shell, 
which  could  not  be  the  case  if  the  animal  was  continually  increasing 
this  hole,  both  in  length  and  breadth,  in  proportion  to  its  growth  ; 
but  if  the  coral  and  the  animal  increase  together,  it  is  then  similar 
to  the  growth  of  all  shells,  whether  bivalve  or  univalve. 

The  animal  does  not  appear  to  have  the  power  of  increasing  its 
canal,  being  only  composed  of  soft  parts.  This,  however  is  no 
argument  against  its  doing  it,  for  every  shell-fish  has  the  power  of 
removing  a part  of  its  shell,  so  as  to  adapt  the  new  and  the  old 
together,  which  is  not  done  by  any  mechanical  power,  but  by  ab- 
sorption.* 

The  tribe  of  animals  which  have  tentacula  consists  of  an  almost 
infinite  variety,  and  many  of  the  species  have  been  described.  Of 
that  kind,  however,  which  has  the  double  cones,  I believe  hitherto 
no  account  has  been  given.  It  is  most  probably  to  be  found  in  the 
seas  surrounding  the  diflerent  islands  in  the  West  Indies,  for  I re- 
ceived an  animal  some  years  ago  from  Mr.  Oliver,  surgeon,  at 
Tenby  in  Pembrokeshire,  which  he  had  procured  from  a gentle- 
man at  St.  Vincent’s,  which,  upon  examination,  proves  to  be  the 
same  animal  with  that  above  described,  only  that  the  moveable 
shell  is  wanting. 

Since  I began  this  Postscript  I find  there  is  a description  of  a 
double-coned  Terebella,  published  by  the  Rev.  Mr.  Cordiner,  at 
Banff  in  Scotland,  which  was  found  upon  that  coast,  in  which  the 
cones  have  their  tentacula  passing  out  from  the  end,  and  when 
erected  they  spread  from  the  cone  as  from  a centre.  This  proves 
that  the  animals  with  double-coned  tentacula  also  have  different 
species. 

* [This  is  best  illustrated  in  the  thinning  of  the  sepia  between  the  different 
whorls  of  the  cones  and  o/ives.  If  the  margins  of  these  septa  be  examined  with 
a pocket  lens,  after  a section  of  the  shell  has  been  made,  it  will  be  found  that 
two  out  of  the  three  layers  of  which  they  were  originally  composed  have  been 
removed.  The  absorption  of  shell  ns  also  illustrated  in  the  removal  or  the 
smoothing  down  of  the  spines  of  the  Munces  ,■  in  the  flattening  of  the  inner  lip 
of  the  mouth  of  the  Purpurse  ,■  in  the  widening  of  the  faecal  aperture  of  the 
Fissurellas,  See.,  &SC,.  These  instances  were  doubtless  well  known  to  Hunter; 
but  the  doctrine  of  the  absorption  of  shell  has  been  lately  adduced  as  a new 
discovery,  in  a recent  volume  of  the  Philosophical  Transactions.  See  Mr.  .T. 
E.  Gray  “On  the  Power  possessed  by  Mollusca  of  dissolving  Shells.”  Phil. 
Trans.  1833,  p.  796.] 


observations  on  some  fossil  bones. 


459 


41.  OBSERVATIONS  ON  THE  FOSSIL  BONES  PRESENT- 
ED TO  THE  ROYAL  SOCIETY  BY  HIS  MOST  SERENE 
HIGHNESS  THE  MARGRAVE  OF  ANSPACH,  ETC. 

BY  THE  LATE  JOHN  HUNTER,  ESQ.,  F.R.S. 

[Communicated  by  Everard  Home,  Esq.,  F.R.S.*] 

The  bones  which  are  the  subject  of  the  present  paper  are  to  be  con- 
sidered more  in  the  light  ofincrusted  bodies  than  extraneous  fossils, 

* [From  the  Philosophical  Transactions,  vol.  Ixxxiv.  ; read  May  8th,  1794. 

The  following'  description,  by  the  Margrave  of  Anspach,  of  the  caves  from 
■which  the  fossils  described  in  the  text  were  taken,  precedes  the  original  memoir. 

“ A ridge  of  primaeval  mountains  runs  almost  through  Germany,  in  a direction 
nearly  from  west  to  east;  the  Hartz,  the  mountains  of  Thuringia,  the  Fichtel- 
berg  in  Franconia,  are  different  parts  of  it,  which  in  their  further  extent  consti- 
tute the  Riesenberg,  and  join  the  Carpathian  mountains.  The  highest  part  of 
this  ridge  are  granite,  and  are  flanked  by  alluvial  and  stratified  mountains,  con- 
sists chiefly  of  limestone,  marl,  and  sandstone;  such  at  least  is  the  tract  of  hills 
in  which  the  caves  to  be  spoken  of  are  situated;  and  over  these  hills  the  main 
road  leads  from  Bayruth  to  Erlang,  or  Nurenberg.  Half-way  to  this  town  lies 
Streitburg,  where  there  is  a post,  and  but  three  or  four  English  miles  distant 
from  thence  are  the  caves  mentioned,  near  Gailenreuth  and  Klausstein,  two  small 
villages,  insignificant  in  themselves,  but  become  famous  for  the  discoveries 
made  in  their  neighbourhood. 

“The  tract  of  hills  is  there  broken  off  by  many  small  and  narrow  valleys,  con- 
fined mostly  by  steep  and  high  rocks,  here  and  there  overhanging,  and  threaten- 
ing, as  it  wm re,  to  fall  and  crush  all  beneath;  and  everywhere  thereabouts  are 
to  be  met  with  objects  which  suggest  the  idea  of  their  being  evident  vestiges  of 
some  general  and  mighty  catastrophe  which  happened  in  the  primseval  times  of 
the  globe. 

“ The  strata  of  these  hills  consist  chiefly  of  limestone  of  various  colour  and  tex- 
ture, or  of  marl  and  sandstones.  The  tract  of  limestone  hills  abounds  with  petri- 
factions of  various  kinds. 

“ The  main  entrance  to  the  caves  at  Gailenreuth  opens  near  the  summit  of  a 
limestone  hill  towards  the  east.  An  arch,  near  seven  feet  high,  leads  into  a kind 
of  ante-chamber,  eighty  feet  in  length,  and  three  hundred  feet  in  circumference, 
which  constitutes  the  vestibule  of  four  other  caves.  This  ante-chamber  is  lofty 
and  airy,  but  has  no  light  except  what  enters  by  its  open  arch  ; its  bottom  is  level, 
and  covered  with  black  mould,  although  the  common  soil  of  the  environs  is  loam 
and  marl. 

“ By  several  circumstances,  it  appears  that  it  has  been  made  use  of  in  turbu- 
lent times  as  a place  of  refuge. 

“ From  this  vestibule,  or  first  cave,  a dark  and  narrow  alley  opens  in  the  cor- 
ner at  the  south  end,  and  leads  into  the  second  cave,  which  is  about  sixty  feet 
long,  eighteen  high,  and  forty  broad.  Its  sides  and  roofs  are  covered,  in  a wild 
and  rough  manner,  with  stalactites,  columns  of  which  are  hanging  from  the 
roof,  others  rising  from  the  bottom,  meeting  the  first  in  many  whimsical  shapes. 

“ The  air  of  this  cave,  as  well  as  of  all  the  rest,  is  always  cool,  and  has,  even 
in  the  height  of  summer,  been  found  below  temperate.  Caution  is  therefore  neces- 
sary to  its  visiters ; for  it  is  remarkable  that  people,  having  spent  any  time  in  this  or 
the  other  caverns,  always  on  their  coming  out  again  appear  pale,  which  in  part 
may  be  owing  to  the  coolness  of  the  air,  and  in  part  likewise  to  the  particular 
exhalations  within  the  caves.  A very  narrow,  winding,  and  troublesome  pas- 
sage opens  further  into  a 

“ Third  cave  or  chamber,  of  a roundish  form,  and  about  thirty  feet  diameter 


4G0 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


since  their  external  surface  has  only  acquired  a covering  of  crys- 
tallized earth,  and  little  or  no  change  has  taken  place  in  their  in- 
ternal structure. 

covered  all  over  with  stalactites.  Very  near  its  entrance  there  is  a perpendicular 
descent  of  about  twenty  feet,  into  a dark  and  frightful  abyss  ; a ladder  must  be 
brought  to  descend  into  it,  and  caution  is  necessary  in  using  it,  on  account  of  the 
rough  and  slippery  stalactites.  When  you  are  down,  you  enter  into  a gloomy 
cave  of  about  fifteen  feet  diameter  and  thirty  feet  high,  making  properly  but  a 
segment  of  the  third  cave. 

“In  the  passage  to  this  third  cave,  some  teeth  and  fragments  of  bones  are 
found  ; but  coming  down  to  the  pit  of  the  cave,  you  are  every  w'ay  surrounded 
by  a vast  heap  of  animal  remains.  The  bottom  of  this  cave  .is  paved  w'ith  a 
stalactical  crust  of  near  a foot  in  thickness  ; large  and  small  fragments  of  all 
sorts  of  bones  are  scattered  everywhere  on  the  surface  of  the  ground,  or  easily 
drawn  out  of  the  mouldering  rubbish.  The  very  walls  seem  filled  with  various 
and  innumerable  teeth  and  broken  bones.  The  stalactical  covering  of  the  uneven 
sides  of  the  cave  does  not  reach  quite  down  to  its  bottom,  whereby  it  plainly  ap- 
pears that  this  vast  collection  of  animal  rubbish  some  time  ago  filled  a higher 
space  in  the  cave,  before  the  bulk  of  it  sunk  by  mouldering. 

“This  place  is  in  appearance  very  like  a large  quarry  of  sandstones  ; and  in- 
deed the  largest  and  finest  blocks  of  osteolithical  concretes  might  be  hewn  out 
in  any  number,  if  there  was  but  room  enough  to  come  to  them,  and  to  carry  them 
out.  Tliis  bony  rock  has  been  dug  into  in  different  places,  and  everywhere 
undoubted  proofs  have  been  met  with,  that  its  bed,  or  this  osteolithical  stratum, 
extends  every  way  far  beneath  and  through  the  limestone  rock  into  which  and 
through  which  these  caverns  have. been  made;  so  that  the  queries  suggesting 
themselves  about  the  astonishing  numbers  of  animals  buried  here  confound  all 
speculation. 

“Along  the  sides  of  this  third  cavern  there  are  some  narrower  openings, 
leading  into  different  smaller  chambers,  of  which  it  cannot  be  said  how  deep 
they  go.  In  some  of  them  bones  of  smaller  animals  have  been  found,  such 
as  jaw-bones,  vertebrte,  and  tibiee,  in  large  heaps.  The  bottom  of  this  cave 
slopes  toward  a passage  seven  feet  high,  and  about  as  wide,  being  the  entrance 
to  a 

“ Fourth  cave,  twenty  feet  high  and  fifteen  w'ide,  lined  all  round  with  a stalac- 
tical crust,  and  gradually  sloping  to  another  deep  descent,  where  the  ladder  is 
wanted  a second  time,  and  must  be  used  with  caution  as  before,  in  order  to  get 
into  a cave  forty  feet  high  and  about  half  as  w'ide.  In  these  deep  and  spacious 
hollows,  worked  out  through  the  most  solid  mass  of  rock,  you  again  perceive 
with  astonishment  immense  numbers  of  bony  fragments  of  all  kinds  and  sizes, 
sticking  everywhere  in  the  aides  of  the  cave,  or  lying  on  the  bottom.  This 
cave  also  is  surrounded  by  several  smaller  ones  ; in  one  of  them  rises  a stalactite 
of  uncommon  bigness,  being  four  feet  high  and  eight  feet  diameter,  in  the  form  of 
a truncated  cone.  In  another  of  those  side  grottos,  a very  neat  stalactical  pillar 
presents  itself,  five  feet  in  height,  and  eight  inches  in  diameter. 

“The  bottom  of  all  these  grottos  is  covered  with  true  animal  mould,  out  of 
which  may  be  drug  fragments  of  bones. 

“ Besides  the  smaller  hollows,  spoken  of  before,  round  this  fourth  cave,  a very 
narrow  opening  has  been  discovered  in  one  of  its  corners.  It  is  of  very  difficult 
access,  as  it  can  be  entered  only  in  a crawling  posture.  This  dismal  and  dan- 
gerous passage  leads  into  a fifth  cave,  of  near  thirty  feet  high,  forty-three  long,  and 
of  unequal  breadth.  To  the  depth  of  six  feet  this  cave  has  been  dug,  and  nothing 
has  been  found  but  fragments  of  bones  and  animal  mould.  The  sides  are  finely 
decorated  with  stalactites  of  different  forms  and  colours  ; but  even  this  stalactical 
crust  is  filled  with  fragments  of  bones  sticking  in  it,  up  to  the  very  roof. 

“ From  this  remarkable  cave  another  very  low  and  narrow  avenue  leads  into 
the  last  discovered,  or  the 

“ Sixth  cave,  not  very  large,  and  merely  covered  with  a stalactical  crust. 


OBSERVATIONS  ON  SOME  FOSSIL  BONES. 


461 


The  earths  with  which  bones  are  most  commonly  incrusted  are 
the  calcareous,  argillaceous,  and  siliceous,  but  principally  the  cal- 
careous; and  this  happens  in  two  ways:  one,  the  bones  being  im- 
mersed in  water  in  wliich  this  earth  is  suspended  ; the  other,  water 
passing  through  masses  of  this  earth,  which  it  dissolves,  and  after- 
wards deposits  upon  bones  which  lie  underneath. 

Bones  which  are  incrusted  seem  never  to  undergo  this  change  in 
the  earth,  or  under  the  water,  where  the  soft  parts  were  destroyed; 
while  bones  that  are  fossilized  become  so  in  the  medium  in  which 
they  were  deposited*  at  the  animal’s  death.  The  incrusted  bones 
have  been  previously  exposed  to  the  open  air:  this  is  evidently  the 
case  with  the  bones  at  present  under  consideration,  those  of  the 
rock  of  Gibraltar,  and  those  found  in  Dalmatia ; and,  from  the 
account  given  by  the  Abbe  Spallanzani,  those  of  the  island  of  Cerigo 
are  under  the  same  circumstances.  They  have  the  characters  of 
exposed  bones,  and  many  of  them  are  cracked  in  a number  of  places, 
particularly  the  cylindrical  bones,  similar  to  the  effects  of  long  ex- 
posure to  the  sun.  This  circumstance  appears  to  distinguish  them 
from  fossilized  bones,  and  gives  us  some  information  respecting 
their  history. 

If  their  numbers  had  corresponded  with  what  we  meet  with  of 
recent  bones,  we  might  have  been  led  to  some  opinion  of  their  mode 
of  accumulation;  but  the  quantity  exceeds  anything  we  can  form 
an  idea  of.  In  an  inquiry  into  their  history  three  questions  naturally 
arise:  Did  the  animals  come  there  and  die?  or.  Were  their  bodies 
brought  there,  and  lay  exposed?  or.  Were  the  bones  collected  from 
different  places?  The  first  of  these  conjectures  appears  to  me  the 
most  natural ; but  yet  I am  by  no  means  convinced  of  its  being  the 
true  one. 

Bones  of  this  description  are  found  in  very  different  situations, 
which  makes  their  present  state  more  difficultly  accounted  for. 
Those  in  Germany  are  found  in  caves;  the  coast  of  Dalmatia  is 
said  to  be  almost  wholly  formed  of  them  ; and  we  know  that  this  is 
the  case  with  a large  portion  of  the  rock  of  Gibraltar. 

If  none  were  found  in  caves,  but  in  solid  masses  covered  with 
marl  or  limestone,  it  would  then  give  the  idea  of  their  having  been 
brought  together  by  some  strange  cause,  as  a convulsion  in  the 
earth,  which  threw  these  materials  over  them  ; but  this  we  can 
hardly  form  an  idea  of.  Or  if  they  had  all  been  found  in  caves,  we 
should  have  imagined  these  caves  were  places  of  retreat  for  such 

in  which,  however,  here  and  there  bones  are  seen  stickingr.  And  here  ends  this 
connected  series  of  most  remarkable  osteolithical  caverns,  as  far  as  they  have 
been  hitherto  explored;  many  more  may  for  what  we  know  exist,  hidden,  in  the 
same  tract  of  hills. 

“Mr.  Esper  has  written  a history  in  German  of  these  caves;  and  given 
descriptions  and  plates  of  a great  number  of  the  fossil  bones  which  have  been 
found  there.  To  this  work  we  must  refer  for  a more  particular  account  of  them.  ”] 

* Bones  that  have  been  buried  with  the  flesh  on  acquire  a strain  which  they 
never  lose,  and  those  which  have  been  long  immersed  in  water  receive  a consider- 
able tinge. 


40* 


462 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


animals,  and  had  been  so  for  some  thousands  of  years;  and  if  the 
bones  were  those  of  carnivorous  animals  and  herbivorous,  we  might 
have  supposed  that  the  carnivorous  had  brought  in  many  animals 
of  a smaller  size  which  they  caught  for  food.  And  this,  upon  the 
first  view,  appears  to  have  been  the  case  with  those  which  are  the 
subject  of  this  paper  ; yet  when  we  consider  that  the  bones  are 
principally  of  carnivorous  animals,  we  are  confined  to  the  supposi- 
tion of  their  being  only  places  of  retreat.  If  they  had  been  brought 
together  by  any  convulsion  of  the  earth,  they  would  have  been 
mixed  with  the  surrounding  materials  of  the  mountains,  which  does 
not  appear  to  be  the  case ; for  although  some  are  found  sticking 
in  the  sides  of  the  caves  incrusted  in  calcareous  matter,  this  seems 
to  have  arisen  from  their  situation  to  the  cave.  Such  accumu- 
lation would  have  made  them  coeval  with  the  mountains  them- 
selves, which  from  the  recent  state  of  the  bones  I should  very  much 
doubt. 

The  difference  in  the  state  of  the  bones  shows  that  there  was  pro- 
bably a succession  of  them  for  a vast  series  of  years  ; for  if  we  con- 
sider the  distance  of  time  between  the  most  perfect  having  been  de- 
posited, which  we  must  suppose  were  the  last,  and  the  present  time, 
we  must  consider  it  to  be  many  thousand  years.  And  if  we  calcu- 
late how  long  these  must  still  remain  to  be  as  far  decayed  as  some 
others  are,  it  will  require  many  thousand  years,  a sufficient  time 
for  a vast  accumulation.  From  this  mode  of  reasoning,  therefore, 
it  would  appear  that  they  were  not  brought  here  at  once  in  a recent 
state. 

The  animal  earth,  as  it  is  called,  at  the  bottom  of  these  caves,  is 
sup>posed  to  be  produced  by  the  rotting  of  the  flesh,  which  is  sup- 
posing the  animals  brought  there  with  the  flesh  on  ; but  I do  con- 
ceive that,  if  the  caves  had  been  stuffed  with  whole  animals,  the 
flesh  could  not  have  produced  one-tenth  part  of  the  earth;  and,  to 
account  for  such  a quantity  as  appears  to  be  the  produce  of  animals, 
I should  suppose  it  the  remains  of  the  dung  of  animals  who  inhabit- 
ed the  caves,  and  the  contents  of  the  bowels  of  those  they  lived  upon. 
This  is  easily  conceived  from  knowing  that  there  is  something  simi- 
lar to  it,  in  a smaller  degree,  in  many  caves  in  this  kingdom,  which 
are  places  of  retreat  for  bats  in  the  winter,  and  even  in  the  summer, 
as  they  only  go  abroad  in  the  evenings.  These  caves  have  their 
bottoms  covered  with  animal  earth,  for  some  feet  in  depth,  in  all 
degrees  of  decomposition,  the  lowermost  the  most  pure,  and  the  up- 
permost but  little  changed,  with  all  the  intermediate  degrees;  in 
which  caves  are  formed  a vast  number  of  stalactites,  which  might 
incrust  the  bones  of  those  that  die  there.* 

* [Hunter  probably  little  suspected  that  there  were  caves  in  this  kingdom,  like 
those  of  Germany,  abounding  with  the  remains  of  extinct  mammalia.  These 
caves,  especially  that  of  Kirkdale  in  Yorkshire,  and  the  fossils  discovered  in 
them,  are  admirably  described  in  the  ‘Reliquiae  Diluvianae’  of  Dr.  Buckland  ; 
and  it  is  gratifying  to  find  that  the  conclusion  which  Hunter  adopted,  out  of  the 
different  hypotheses  which  he  suggests  to  account  for  the  presence  of  the  bears’ 
bones  in  the  Bayreuth  caverns,  viz.,  that  these  had  served  as  an  habitual  retreat 


OBSERVATIONS  ON  SOME  FOSSIL  BONES. 


463 


The  bones  in  the  caves  in  Germany  are  so  much  the  object  of 
the  curious  that  the  specimens  are  dispersed  throughout  Europe, 
which  prevent  a sufficient  number  coming  into  the  hands  of  any 
one  person  to  make  him  acquainted  with  the  animals  to  which  they 
belong. 

From  the  history  and  figures  given  byEsper  it  appears  that  there 
are  the  bones  of  several  animals  ; but  what  is  curious,  they  all  ap- 
pear to  have  been  carnivorous,  which  we  should  not  have  expected. 
There  are  teeth,  in  number,  kind,  and  mode  of  setting,  exactly  simi- 
lar to  the  white  bear,  others  more  like  those  of  the  lion  ; but  the 
representations  of  parts,  however  well  executed,  are  hardly  to  be 
trusted  to  for  the  nicer  characters,  and  much  less  so  when  the  parts 
are  mutilated.* 

The  bones  sent  by  his  Highness  the  Margrave  of  Anspach  agree 
with  those  described  and  delineated  by  Esper  as  belonging  to  the 
W'hite  bear ; how  far  they  are  of  the  same  species  among  themselves 
I cannot  say.  The  heads  differ  in  shape  from  each  other ; they 
are,  upon  the  whole,  much  longer  for  their  breadth  than  in  any 
canivorous  animal  I know  of:  they  also  differ  from  the  present 
white  bear,  which,  as  far  as  I have  seen,  has  a common  propor- 
tional breadth.  It  is  supposed,  indeed,  that  the  heads  of  the  present 
white  bear  differ  from  one  another;  but  the  truth  of  this  assertion 
I have  not  seen  heads  enough  of  that  animal  to  determine. 

The  heads  not  only  vary  in  shape  but  also  in  size  ; for  some  of 
them,  when  compared  with  the  recent  white  bear,  would  seem  to 
have  belonged  to  an  animal  twice  its  size  : while  some  of  the  bones 
correspond  in  size  with  those  of  the  white  bear,  and  others  are  even 
smaller.! 

There  are  two  ossa  humeri,  rather  of  a less  size  than  those  of 
the  recent  white  bear  ; a first  vertebra,  rather  smaller ; the  teeth  also 
vary  considerably  in  size,  yet  they  are  all  those  of  the  same  tribe  ; 
so  that  the  variety  among  themselves  is  not  less  than  between  them 
and  the  recent. 

In  the  formation  of  the  head,  age  makes  a considerable  differ- 
ence : the  skull  of  a young  dog  is  much  more  rounded  than  an  old 
one  ; the  ridge  leading  baek  to  the  occiput,  terminating  in  the  two 
lateral  ones,  hardly  exists  in  a young  dog;  and  among  the  present 
bones  there  is  the  back  part  of  such  a head,  yet  it  is  larger  than  the 

to  the  living  animals,  and  had  thus  become  the  depository  of  the  remains  of 
successive  generations,  agrees  with  the  theory  proposed  by  Dr.  Buckland  with 
reference  to  the  bones  of  the  hyeenas,  accumulated  at  Kirkdale,  the  chief  argu- 
ment in  support  of  which  is  derived  from  the  abundance  of  earthy  or  bony  dung 
with  which  the  fossils  are  associated.] 

* [Remains  of  an  indubitably  large  feline  animal  have  been  found  associated 
with  the  bears’  bones  in  the  Bayreuth  and  Gaybureuth  caverns.  'I'he  mutilated 
cranium  figured  by  Leibnitz  in  his  Protogaea,  PI.  XL,  is  considered  by  Soem- 
mering to  have  belonged  to  a lion.] 

! It  is  to  be  understood  that  the  bones  of  the  white  bear  that  I have,  belonged 
to  one  that  had  been  a show,  and  had  not  grown  to  tlie  full  or  natural  size;  and 
I make  allowance  for  this  in  my  assertion  that  the  heads  of  those  incrustcd  appear 
to  belong  to  an  animal  twice  the  size  of  our  white  bear. 


464 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


head  of  the  largest  mastiff;  how  far  the  young  white  bear  may 
vary  from  the  old,  similar  to  the  young  dog,  I do  not  know,  but  it 
is  very  probable.* 

Bones  of  animals  under  circumstances  so  similar,  although  in 
different  parts  of  the  globe,  one  would  have  naturally  supposed  to 
consist  chiefly  of  those  of  one  class  or  order  in  every  place,  one 
principle  acting  in  all  places.f  In  Gibraltar  they  are  mostly  of  the 
ruminating  tribe,  of  the  hare  kind,  and  the  bones  of  birds;  yet  there 
are  some  of  a small  dog  or  fox,  and  likewise  shells.  Those  in 
Dalmatia  appear  to  be  mostly  of  the  ruminating  tribe  ; yet  I saw 
a part  of  the  os  hyoides  of  a horse;  but  those  from  Germany  are 
mostly  carnivorous.  From  these  facts  we  should  be  inclined  to 
suppose  that  their  accumulation  did  not  arise  from  any  instinctive 
mode  of  living,  as  the  same  mode  could  not  suit  both  carnivorous 
and  herbivorous  animals. f 

In  considering  animals  respecting  their  situation  upon  the  globe, 
there  are  many  which  are  peculiar  to  particular  climates,  and  others 
that  are  less  confined,  as  herrings,  mackerel,  and  salmon  ; others 
again  which  probably  move  over  the  whole  extent  of  the  sea,  as 
the  shark,  porpus,  and  whale  tribe  ; while  many  shell-fish  must  be 
confined  to  one  spot.§  If  the  sea  had  not  shifted  its  situation  more 
than  once,  and  was  to  leave  the  land  in  a very  short  time,  then  we 
could  determine  what  the  climate  had  formerly  been  by  the  extra- 
neous fossils  of  the  stationary  animals,  for  those  only  would  be 
found  mixed  with  those  of  passage  ; but  if  the  sea  moves  from  one 
place  to  another  slowly%  then  the  remains  of  animals  of  different 
climates  may  be  mixed,  by  those  of  one  climate  moving  over  those 
of  another,  dying,  and  being  fossilized  ; but  this  I am  afraid  cannot 

* [There  are  now  skulls  of  the  young  and  old  white  bear  in  the  Collection  of 
the  College  of  Surgeons  in  London  which  confirm  Hunter’s  conjecture  respecting 
the  difference  of  form  which  is  due  to  age  in  this  genus.  It  will  be  seen  that 
Hunter  adduces  this  circumstance  merely  as  one  which  must  be  taken  into  consi- 
deration in  comparing  recent  and  fossil  crania  of  the  same  genus  ; and  that  he  by 
no  means  asserts,  as  Cuvier  states  he  does,  that  the  differences  which  he  had 
detected  between  the  fossil  and  recent  skulls,  and  between  the  different  fossil 
skulls  of  the  cave  bears,  are  of  the  same  nature  and  degree. — Ossemens  Fosstles, 
6me  Ed.,  tom.  vii.,  p.  23G. 

f [This  sagacious  conjecture  has  received  remarkable  confirmation  from  recent 
discoveries  ; the  fossil  bones  that  have  been  found  in  Australia  appertain  for  the 
most  part  to  animals  of  the  marsupial  order,  and  those  collected  in  South  America 
contain  a remarkable  proportion  of  Edentata,  some  of  them  of  gigantic  propor- 
tions, but  all  protected  by  a bony  armour  analogous  to  that  of  the  armadillos, 
which  are  peculiar  to  South  America.] 

f:  [Mr.  Lyell  thus  describes  some  of  the  circumstances  under  which  the  bones 
of  animals  are  accumulated  at  Gibraltar:  “At  the  north  extremity  of  the  rock 
are  perpendicular  fissures,  on  the  ledges  of  which  a number  of  hawks  nestle  and 
rear  their  young  in  the  breeding  season.  They  throw  down  from  their  nests 
the  bones  of  small  birds,  mice,  and  other  animals,  on  which  they  feed,  and  these 
are  gradually  united  into  a breccia  of  angular  fragments  of  the  decomposing 
limestone  with  a cement  of  red  earth.”  (Principles  of  Geology,  vol.  iii.,  p.  158.) 

§ [Por  a full  development  of  the  relation  which  the  geographical  distribution 
of  animals  bears  to  the  science  of  Oryctology,  or  Fossil  Remains,  the  reader  is 
referred  to  the  second  and  third  volumes  of  Lyell’s  Principles  of  Geology.] 


OBSERVATIONS  ON  SOME  FOSSIL  BONES. 


465 


be  made  out.  By  the  fossils  we  may,  however,  have  some  idea 
how.  the  bones  of  the  land  animals  fossilized  may  be  disposed  with 
respect  to  those  of  the  sea. 

If  the  sea  should  have  occupied  any  space  that  never  had  been 
dry  land  prior  to  the  sea’s  being  there,  the  extraneous  fossils  can 
only  be  those  of  sea  animals ; but  each  part  will  have  its  particular 
kind  of  those  that  are  stationary  mixed  with  a few  of  the  amphibia, 
and  of  sea  birds,  in  those  parts  that  were  the  skirts  of  the  sea.  I 
shall  suppose  that  when  the  sea  left  its  place  it  moved  over  land 
where  both  vegetables  and  land  animals  had  existed,  the  bones  of 
which  will  be  fossilized,  as  also  those  of  the  sea  animals;  and  if  the 
sea  continued  long  here,  which  there  is  reason  to  believe,  then  those 
mixed  extraneous  fossils  will  be  covered  with  those  of  sea  animals. 
Now  if  the  sea  should  again  move,  and  abandon  this  situation,  then 
we  should  find  the  land  and  sea  fossils  above  mentioned  disposed  in 
this  order;  and  as  we  begin  to  discover  extraneous  fossils  in  a 
contrary  direction  to  their  formation,  we  shall  first  find  a stratum 
of  those  of  animals  peculiar  to  the  sea,  which  were  the  last  formed, 
and  under  it  one  of  vegetables  and  land  animals,  which  were  there 
before  they  were  covered  by  the  sea,  and  among  them  those  of  the 
sea,  and  under  this  the  common  earth.  Those  peculiar  to  the  sea 
will  be  in  depth  in  proportion  to  the  time  of  the  sea’s  residence  and 
other  circumstances,  as  currents,  tides,  &c. 

From  a succession  of  such  shiftings  of  the  situations  of  the  sea 
we  may  have  a stratum  of  marine  extraneous  fossils,  one  of  earth, 
mixed  probably  with  vegetables  and  bones  of  land  animals,  a stratum  of 
terrestrial  extraneous  fossils,  then  one  of  marine  productions  ; but 
from  the  sea  carrying  its  inhabitants  along  with  it,  wherever  there 
are  those  of  land  animals  there  will  also  be  a mixture  of  marine 
ones;  and  from  the  sea  commonly  remaining  thousands  of  years  in 
nearly  the  same  situation,  we  have  marine  fossils  unmixed  with 
any  others.’^ 

All  operations  respecting  the  growth  or  decomposition  of  animal 
and  vegetable  substances  go  on  more  readily  on  the  surface  of  the 
earth  than  in  it ; the  air  is  most  probably  the  great  agent  in  de- 
composition and  combination,  and  also  a certain  degree  of  heat. 
Thus  the  deeper  we  go  into  the  earth  we  find  the  fewer  changes 
going  on  ; and  there  is  probably  a certain  depth  where  no  change 
of  any  kind  can  possibly  take  place.  The  operation  of  vegetation 
will  not  go  on  at  a certain  depth,  but  at  this  very  depth  a 
decomposition  can  take  place,  for  the  seed  dies  and  in  time  decays  ; 
but  at  a still  greater  depth  the  seed  retains  its  life  for  ages,  and 

* [The  importance  of  the  study  of  fossil  remains  in  the  elucidation  of  the  nature 
of  the  changes  to  which  the  earth’s  surface  has  been  subject,  here  dwelt  upon  by 
Hunter,  was  placed  in  a strong  light  by  the  subsequent  researches  of  Cuvier  and 
Brogniart  on  the  structure  of  the  Paris  Basin,  and  the  fossils  which  have  rendered 
it  so  famous.  By  the  aid  of  these  fossils  Cuvier  was  enabled  to  refer  the  suc- 
cession of  strata  to  several  distinct  alternations  of  marine  and  freshwater  forma- 
tions.] 


466 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


when  bi’ought  near  enough  to  the  surface  for  vegetation  it  grows. 
Something  similar  to  this  takes  place  with  respect  to  extraneous 
fossils;  for  although  a piece  of  wood  or  bone  is  dead  when  so 
situated  as  to  be  fossilized,  yet  they  are  sound  and  free  from  decompo- 
sition, and  the  depth,  joined  with  the  matter  in  which  they  are 
often  found,  as  stone,  clay,  &c.,  preserves  them  from  putrefaction, 
and  their  dissolution  requires  thousands  of  years  to  complete  it; 
probably  they  may  be  under  the  same  circumstances  as  in  a vacuum  ; 
the  heat  in  such  situations  is  uniform,  probably  in  common  about  52° 
or  53°,  and  in  the  colder  regions  they  are  still  longer  preserved. 

I believe  it  is  generall}^  understood  that  in  extraneous  fossils  the 
animal  part  is  destroyed,  but  I find  that  this  is  not  the  case  in  any  I 
have  met  with. 

Shells,  and  bones  of  fish, most  probably  have  the  least  in  quantity, 
having  been  longest  in  that  state  ; otherwise  they  should  have  the 
most ; for  the  harder  and  more  compact  the  earth,  the  better  is  the 
animal  part  preserved,  which  is  an  argument  in  proof  of  their  having 
been  the  longest  in  a fossil  state.  From  experiment  and  observa- 
tion the  animal  part  is  not  allowed  to  putrefy  ; it  appears  only  to 
be  dissolved  into  a kind  of  mucus,  and  can  be  discovered  by  dis- 
solving the  earth  in  an  acid  : when  a shell  is  treated  in  this  way 
the  animal  substance  is  not  fibrous  or  laminated,  as  in  the  recent 
shell,  but  without  tenacity,  and  can  be  washed  off  like  wet  dust;  in 
some,  however,  it  has  a slight  appearance  of  flakes. 

In  the  shark’s  tooth,  or  glosso-petra,  the  enamel  is  composed  of 
animal  substance  and  calcareous  earth,  and  is  nearly  in  the  same 
quantity  as  in  the  recent ; but  the  central  part  of  the  tooth  has  its 
animal  substance  in  the  state  of  mucus  interspersed  in  the  calcare- 
ous matter. 

In  the  fossil  bones  of  sea  animals,  as  the  vertebrae  of  the  whale, 
the  animal  part  is  in  large  quantity,  and  in  two  states,  the  one 
having  some  tenacity,  but  the  other  like  wet  dust;  but  in  some  of 
the  harder  bones  it  is  more  firm.  In  the  fossil  bones  of  land  ani- 
mals, and  those  which  inhabit  the  waters,  as  the  sea-horse,  otter, 
crocodile,  and  turtle,  the  animal  part  is  in  considerable  quantity. 
In  the  stags’  horns  dug  up  in  Great  Britain  and  Ireland,  when  the 
earth  is  dissolved,  the  animal  part  is  in  considerable  quantity,  and 
very  firm.  The  same  observations  apply  to  the  fossil  bones  of  the 
elephant  found  in  England,  Siberia,  and  other  parts  of  the  globe; 
also  those  of  the  ox  kind  ; but  more  particularly  to  their  teeth, 
especially  those  from  the  lakes  in  America,  in  which  the  animal 
part  has  suffered  very  little;  the  inhabitants  find  little  difference 
in  the  ivory  of  such  tusks  from  the  recent,  but  its  having  a yellow 
stain  ; the  cold  may  probably  assist  in  their  preservation. 

The  state  of  preservation  will  vary  according  to  the  substance  in 
which  they  have  been  preserved  ; in  peat  and  clay  I think  the  most ; 
however,  there  appears  in  general  a species  of  dissolution,  for  the 
animal  substance,  although  tolerably  firm,  in  a heat  a little  above 
100°  becomes  a thickish  mucus,  like  dissolved  gum,  while  a portion 
from  the  external  surface  is  reduced  to  the  state  of  wet  dust. 


OBSERVATIONS  ON  SOME  FOSSIL  BONES. 


467 


In  incrusted  bones  the  quantity  of  animal  substance  is  very  dif- 
ferent in  different  bones.  In  those  from  Gibraltar  there  is  very 
little  ; it  in  part  retains  its  tenacity,  and  is  transparent,  but  the  super- 
ficial part  dissolves  into  mucus. 

Those  from  Dalmatia  give  similar  results  vrhen  examined  in  this 
way. 

Those  from  Germany,  especially  the  harder  bones  and  teeth, 
seem  to  contain  all  the  animal  substance  natural  to  them  ; they 
differ,  however,  among  themselves  in  this  respect. 

The  bones  of  land  animals  have  their  calcareous  earth  united  with 
the  phosphoric  acid  instead  of  the  aerial,^  and  I believe  retain  it 
when  fossilized,  nearly  in  proportion  to  the  quantity  of  animal  matter 
they  contain. 

The  mode  by  which  I judge  of  this  is  by  the  quantity  of  effer- 
vescence ; when  fossil  bones  are  put  into  the  muriatic  acid  it  is  not 
nearly  so  great  as  when  a shell  is  put  into  it,  but  it  is  more  in  some, 
although  not  in  all,  than  when  a recent  bone  is  treated  in  this  way, 
and  this  I think  diminishes  in  proportion  to  the  quantity  of  animal 
substance  they  retain  ; as  a proof  of  this,  those  fossil  bones  which 
contain  a small  portion  of  animal  matter  produce  in  an  acid  the 
greatest  effervescence  when  the  surface  is  acted  on,  and  very  little 
when  the  centre  is  affected  by  it ; however,  this  may  be  accounted 
for  by  the  parts  which  have  lost  their  phosphoric  acid,  and  acquired 
the  aerial,  being  easiest  of  solution  in  the  marine  acid,  and  there- 
fore dissolved  first,  and  the  aerial  acid  let  loose. 

In  some  bones  of  the  whale  the  effervescence  is  veiy  great;  in 
the  Dalmatia  and  Gibraltar  bones  it  is  less  ; and  in  those  the  subject 
of  the  present  paper  it  is  very  little,  since  they  contain  by  much  the 
largest  proportion  of  animal  substance.f 

* [Carbonic.] 

)■  [In  this  Paper  we  may  perceive  that  Hunter  appreciated  the  value  of  the 
study  of  Fossil  Remains,  and  their  application  to  the  elucidation  of  many  im- 
portant subjects.  First,  with  reference  to  the  extension  of  our  ideas  respecting 
the  zoology  of  this  planet,  we  find  him  comparing  the  fossils  which  are  the  sub- 
ject of  the  text,  with  their  recent  analogues,  and  he  sliows  that  they  differ  both 
from  them  and  among  themselves  : his  observations  and  comparisons  are,  it  is 
true,  too  general  and  summary,  and  it  was  left  to  his  successors  in  this  field  of 
inquiry  to  pursue  the  comparison  with  the  requisite  minuteness  and  precision, 
and  to  give  names  to  the  distinctbut  extinct  species.  Hunter  next  briefly  alludes 
to  the  different  situations  and  climates  in  the  globe,  to  which  animals  are  more 
or  less  confined  ; and  this  subject,  or  the  geographical  distribution  of  animals, 
considered  in  relation  to  fossil  remains,  elucidates,  amongst  other  interesting 
questions,  the  changes  of  temperature  to  which  different  parts  of  the  earth  have 
been  subject  at  different  epochs.  Hunter  points  out  more  distinctly,  and  with 
more  detail,  the  evidence  which  extraneous  fossils  afford  respecting  the  alterna- 
tions of  land  and  sea,  of  which  the  earth’s  surface  has  been  the  theatre  ; and  by 
his  frequent  allusion  to  the  “ many  thousand  years  ” which  must  have  elapsed 
during  these  periods,  seems  to  have  fully  appreciated  the  necessity  of  an  ample 
allowance  of  past  time  in  order  to  account  philosophically  for  the  changes  in 
question.  Lastly,  he  treats  of  the  nature  and  causes  of  the  different  states  in 
which  the  remains  of  extinct  animals  are  found;  and  many  of  the  fossil  bones 
which  were  the  subject  of  his  chemical  experiments  are  still  preserved  in  his 
museum  (see  Nos.  118-130,  Physiological  Series.) 

When  we  turn  from  the  perusal  of  this  highly  philosophical  memoir  to  the 


468 


HUNTER  ON  THE  ANIMAL  (ECONOMY. 


42.  DESCRIPTIONS  OF  SOME  ANIMALS  FROM  NEW 
SOUTH  WALES. 

BY  JOHN  HUNTER,  F.R.S. 

[The  following  descriptions  are  interesting,  not  less  from  being 
the  first  that  appeared  of  some  of  the  most  singular  of  the  qua- 
drupeds which  characterize  the  Fauna  of  Australia,  than  from  the 
celebrity  of  their  author,  of  whose  contributions  to  descriptive 
zoology  they  are  almost  the  only  examples.  They  form  part  of 
the  zoological  appendix  to  a “Journal  of  a voyage  to  New  South 
Wales,  4to.  1790,”  published  by  John  White,  Esq.,  Surgeon-General 
to  the  settlement,  who  thus  acknowledges  the  assistance  which  he 
derived  from  the  gentlemen  by  whose  cooperation  he  was  “ enabled 
to  surmount  those  difficulties  that  necessarily  attended  the  descrip- 
tion of  so  great  a variety  of  animals,  presented  for  the  first  time  to 
the  observation  of  the  naturalist,  and  consequently  in  the  class  of 
nondescripts.  Among  those  gentlemen  he  has  the  honour  particu- 
larly to  reckon  the  names  of  Dr.  Shaw,  Dr.  Smith,  the  possessor 
of  the  celebrated  Liniicean  Collection;  and  John  Hunter,  Esq., 
who  to  a sublime  and  inventive  genius,  happily  unites  a disinterested 
and  generous  zeal  for  the  promotion  of  natural  science.” 

Dr.  Shaw,  who  superintended  the  publication  of  White’s  Zoolo- 
gical Appendix,  thus  introduces  the  observations  contributed  by 
Hunter : — 

“ The  nondescript  animals  of  New  South  Wales  occupied  a great 
deal  of  Mr.  White’s  attention,  and  he  preserved  several  specimens 
of  them  in  spirits,  which  arrived  in  England  in  a very  perfect  state. 
There  was  no  person  to  whom  these  could  be  given  with  so  much 
propriety  as  Mr.  Hunter,  he,  perhaps,  being  most  capable  of  ex- 

notice  of  it  in  the  Ossemens  Fossils  of  Cuvier,  we  must  suppose  that  it  could  have 
been  but  very  imperfectly  known  to  the  great  founder  of  oryctological  science. 
In  the  chapter  on  tlie  ‘Ours  Fossiles,’ Cuvier  says:  “ Le  c^lebre  chirurgeon 
anglais,  J.  Hunter,  dans  un  Memoire  sur  les  os  fossiles,  qui  n'a  que  leur  analyse 
cliimique  pour  ohjet,  et  qui  est  insere  dans  les  Transactions  Philosophiques, 
donne  deux  belles  figures  de  cranes  d’ours  fossiles  les  meillures  qui  aient  paru 
jusque  la,  mais  sans  description  detaillee,  et  en  disant  pour  toute  comparaison 
que  les  differentes  tetes  d’ours  de  cavernes  different  autant  entre  elles  qu’elles 
different  de  Pours  polaire,  et  que  toutes  ces  differences  ne  surpassent  point  celles 
que  I’age  peut  produire  dans  les  animaux  carnassiers  ; assertion  vague  et  meme 
erronee.” — Loc.  cit.,  p.  237. 

A careful  and  candid  perusal  of  Hunter’s  Memoir  would  doubtless  have 
exonerated  the  author  from  this  charge  in  the  mind  of  Cuvier,  as  it  must  do  in 
that  of  every  unprejudiced  reader.  Hut  it  would  still  afford  a very  inadequate 
notion  of  the  extent  to  which  Hunter  had  pursued  his  study  of  fossil  remains. 
The  interest  that  he  took  in  them  is  shown  by  the  frequent  exhortations  towards 
their  collection  in  his  letters  to  Jenner,  and  liis  collection  at  his  decease  included 
about  1050  specimens,  of  which  there  are  259  belonging  to  the  vertebrate  classes 
(including  70  specimens  of  fossil  fisltes,  and  40  of  reptiles),  116  cephalopods, 
116  univalves,  143  bivalves,  35  Crustacea,  163  echinodermata,  109  zoophytes, 
and  50  fossil  vegetable  productions.] 


DESCRIPTIOxXS  OF  SOME  ANIMALS,  ETC. 


469 


arnining  accurately  their  structure,  and  making  out  their  place  in 
the  scale  of  animals ; andjt  is  to  him  that  we  are  indebted  for  the 
following  observations  upon  them,  in  which  the  anatomical  structure 
is  purposely  avoided,  as  being  little  calculated  for  the  generality  of 
readers  of  a work  of  this  kind.”] 

It  is  much  to  be  wished  that  those  gentlemen  who  are  desirous 
of  obliging  their  friends,  and  promoting  the  study  of  natural  history, 
by  sending  home  specimens,  would  endeavour  to  procure  all  the 
information  they  can  relating  to  such  specimens  as  they  may  collect, 
more  especially  animals. 

The  subjects  themselves  may  be  valuable,  and  may  partly  explain 
their  connection  with  those  related  to  them,  so  as  in  some  measure  to 
establish  their  place  in  nature,'*  but  they  cannot  do  it  entirely  ; they 
only  give  us  the  form  and  construction,  but  leave  us  in  other  re- 
spects to  conjecture,  many  of  them  requiring  further  observation 
relative  to  their  osconomy. 

A neglect  in  procuring  this  information  has  left  us  almost  to  this 
day  very  ignorant  of  that  part  of  the  natural  history  of  animals 
which  is  the  most  interesting.  The  Opossum  is  a remarkable  in- 
stance of  this.  There  is  something  in  the  mode  of  propagation  in 
this  animal,  that  deviates  from  all  others;  and  although  known  in 
some  degree  to  be  extraordinary,  yet  it  has  never  been  attempted, 
where  opportunity  offered,  to  complete  the  investigation.  I have 
often  endeavoured  to  breed  them  in  England  ; I have  bought  a 
great  many,  and  my  friends  have  assisted  me  by  bringing  them  or 
sending  them  alive,  yet  never  could  get  them  to  breed  ; and  although 
possessed  of  a great  many  facts  respecting  them,  I do  not  believe 
my  information  is  sufficient  to  complete  the  system  of  propagation 
in  this  class.f 

* [It  is  interesting  to  meet  with  these  indications  of  the  spirit  in  which  Hunter 
prosecuted  his  zoological  researches.  To  ascertain  the  affinities  of  the  animals 
whose  structure  he  explored,  or,  in  other  words,  to  establish  a natural  system  of 
classification,  was  not  less  the  aim  of  Hunter  than  the  determination  of  the 
functions  of  the  different  organs  in  the  animal  frame  ; and  the  truth  of  the  remark 
of  the  necessity  of  combining  observation  of  the  living  habits  of  animals,  with 
anatomical  and  zoological  research,  in  order  to  establish  entirely  their  place 
in  nature,  as  well  as  to  fully  understand  their  (economy,  is  now  universally 
admitted.] 

f [Since  the  time  of  Mr.  Hunter,  the  kangaroo  by  breeding  in  this  country  has 
afforded  the  opportunity  of  elucidating  many  of  the  peculiarities  of  the  generative 
(economy  of  the  Marsupial  quadrupeds.  These  peculiarities  are  not  confined  to 
the  female.  In  the  male,  the  testicles  are  situated  in  an  exte  rnal  fold  of  the  in- 
tegument, corresponding  in  situation  to  the  internal  fold  which  constitutes  the 
marsupial  pouch  in  the  female,  and  the  scrotum  thus  formed  is  consequently 
anterior  to  the  penis.  The  cremaster  muscles  wind  round  the  supplementary 
bones  attached  to  the  pubis,  which  act  as  fulcra  to  the  muscles,  and  enable  them 
to  compress  the  gland  with  a force  which  seems  to  be  demanded  in  consequence 
of  the  tortuosity  of  the  double  vagina  along  which  the  semen  has  to  be  propelled. 
Tfie  coitus  is  of  long  duration  in  the  kangaroo,  and  the  scrotum  disappear  during 
the  forcible  retraction  of  the  testes  against  the  marsupial  bones. 

The  female  kangaroo  is  pregnant  for  the  space  of  thirty-eight  days,  when 
Uterine  birth  takes  place,  and  the  embryo,  now  about  an  inch  in  length,  is 

41 


470 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


In  collecting  animals,  even  the  name  given  by  the  natives  if 
possible  should  be  known,  for  a name  to  a naturalist  should  mean 
nothing  but  that  to  which  it  is  annexed,  having  no  allusion  to  any- 
thing else,  for  when  it  has  it  divides  the  idea.  This  observation 

applies  particularly  to  the  animals  which  have  come  from  New 

transferred,  I suspect,  by  the  mouth  of  the  parent,  from  the  vulva  to  the  nipple, 
where  it  hangs,  protected  and  concealed  by  the  pouch  for  about  six  months. 

Only  two  opportunities  have  as  yet  occurred  for  the  examination  of  the  uterine 
fcEtus.  These  show  that  it  is  nourished  chiefly  by  means  of  omphalo-mesenteric 
vessels,  which  ramify  over  a large  vitelline  sac.  When  the  extremities  are 
formed,  and  the  uterine  foetus  has  attained  about  two-thirds  its  size  as  such,  an 
allantois  is  developed  ; the  umbilical  arteries  coextended  with  this  sac  do  not, 
however,  as  in  the  placental  mammalia,  pass  to  the  chorion;  but  this  membrane 
continues  unorganized,  as  in  the  ovoviviparous  and  oviparous  classes,  and  con- 
sequently there  is  no  adhesion  of  the  foetal  membranes  to  the  uterine  parietes, 
and  therefore  no  obstruction  to  the  escape  of  the  embryo  (at  the  premature  period 
destined  for  its  birth)  from  the  uterus  into  the  vagina. 

The  uterus  is  double  in  all  the  marsupiata,  and  each  cavity  is  of  small  size, 
and  of  a simple  elongated  form.  In  the  Didelphis  dorsigera,  each  os  tincae  opens 
into  a long  vagina,  which  makes  a sweep  outwards,  and  then  converging  towards 
its  fellow,  opens  into  the  upper  end  of  a cloacal  passage,  common  to  the  two 
vaginae  and  the  urethra.  In  the  Virginian  opossum,  eatdi  vagina,  before  describ- 
ing the  outward  curvature,  sends  down  a cul-de-sac,  which  is  closely  united  to 
the  one  on  the  opposite  side,  but  the  cavities  are  distinct.  In  the  kangaroo,  the 
two  cul-de-sacs  are  blended  together,  so  that  the  vagincs  communicate  together 
noth  at  their  commencement,  and  also  at  their  termination  in  the  meatus  com- 
munis. The  size  of  the  vaginal  cul-de-sacs  seems  to  be  in  the  ratio  of  the  capacity 
of  the  external  pouch. 

The  embryo  is  adapted  to  its  intra-marsupial  existence  by  a precocious  develop- 
ment of  the  respiratory  and  circulating  organs,  by  a peculiar  tubular  form  of  the 
mouth,  and  a grooved  tongue  calculated  to  retain  a firm  hold  on  the  elongated 
nipple ; it  has  also  a peculiar  construction  of  the  larynx,  somewhat  analogous  to 
that  of  the  whale,  by  which  respiration  may  be  safely  continued  in  the  foetus 
while  the  mother  injects  the  milk  down  its  pharynx.  It  would  seem  that  the 
new-born  marsupial  is  incompetent  from  its  feeble  and  incomplete  structure  to 
the  office  of  forcing  a stream  of  milk  through  the  long  and  tortuous  lacteal  ducts, 
since  the  mammary  gland  is  embraced  by  a muscle,  corresponding  to  the  cre- 
master in  the  male,  and  winding  in  a similar  manner  round  the  marsupial  bones  ; 
these  therefore  aid  the  expulsion  of  the  milk  in  the  female,  as  they  do  that  of 
the  semen  in  the  male  ; they  also  in  the  female  add  to  the  power  of  the  mammary 
muscles  in  sustaining  a portion  of  the  weight  of  the  foetus  which  is  attached  to 
the  nipple. 

Many  have  been  the  conjectures  respecting  the  final  intention  of  the  premature 
birth  of  the  marsupial  animal,  and  of  the  various  singular  modifications  of  struc- 
ture necessitated  by,  and  adapted  to  that  circumstance.  Since  it  obtains  in 
quadrupeds  of  almost  every  variety  of  form,  and  with  various  modes  of  locomotion 
and  diversity  of  diet,  it  must  result  from  some  more  general  law  than  individual 
proportions  or  habits  of  the  parent.  It  is  associated  with  a marked  inferiority  of 
cerebral  organization  ; but  the  final  purpose  will  be  most  probably  discovered  to 
relate  to  some  peculiarity  in  the  physical  geography  of  that  portion  of  the  globe 
in  which  the  quadrupeds  almost  exclusively  exhibit  the  marsupial  organization. 
Long-continued  droughts  and  a scarcity  of  freshwater  streams  are  amongst  the  most 
striking  features  of  the  climate  and  territory  of  Australia  ; and  when  we  reflect  that 
the  principal  exceptions  to  the  marsupial  organization,  viz.,  the  Ornithorhynchus 
and  the  Hydromys,  or  water-rat  of  the  colonists,  habitually  inhabit  thefroshw'ater 
ponds,  the  peculiarities  of  the  reproduction  above  described  may  have  reference 
to  the  great  distances  which  the  mammalia  of  New  South  Wales  are  generally 
compelled  to  traverse  in  order  to  quench  their  thirst.] 


DESCRIPTIONS  OF  SOME  ANIMALS,  ETC. 


471 


Holland;  they  are,  upon  the  whole,  like  no  other  that  we  yet  know 
of,  but  as  they  have  parts  in  some  respects  similar  to  others,  names 
will  naturally  be  given  to  thetn  expressive  of  those  similarities, 
which  has  already  taken  place  ; for  instance,  one  is  called  the 
kangaroo  rat,  but  which  should  not  be  called  either  kangaroo  or 
rat;  I have  therefore  adopted  such  names  as  can  only  be  appro- 
priated to  each  particular  animal,  conveying  no  other  idea.* 

Animals  admit  of  being  divided  into  great  classes,  but  will  not 
so  distinctly  admit  of  subdivision  without  interfering  with  each 
other.  Thus  the  class  called  quadrupeds  is  so  well  marked  that 
even  the  whole  is  justly  placed  in  the  same  class,  birds  the  same, 
amphibia  (as  they  are  called)  the  same,  and  so  of  fishes,  &c. ; but 
when  we  are  subdividing  these  great  classes  into  their  diflerent 
tribes,  genera  and  species,  then  we.  find  a mixture  of  properties, 


* [The  evils  of  implying  false  affinities  and  of  suppressing  differences  of  pri- 
mary importance,  which  would  have  resulted  from  referring  the  newly  discovered 
quadrupeds  of  Australia  to  the  known  Linnaean  genera,  as  was  afterwards  done 
by  Dr.  Shaw,  were  sagaciously  avoided  by  Hunter.  And  had  tlie  same  expanded 
views  been  taken  by  his  colleague,  zoology  would  not  at  the  present  time  have 
been  burdened  with  such  useless  synonyms  as  Didelphys  petaurus,  Didelphys 
penicillata,  Didelphys  viverrina,  Didelphys  obesula,  &c.,  and  the  zoologists  of  the 
continent  might  have  been  spared  the  task  of  rectifying  the  errors  of  that  arrange- 
ment, which  arising  from  an  ignorance  of  the  anatomical  distinctions  of  the 
animals  in  question,  and  from  a disregard  of  the  modifications  presented  by  their 
teeth  and  locomotive  extremities,  consisted  in  grouping  with  the  American 
opossums  the  species  above  quoted, — species  which  now  form  respectively  the 
types  of  the  genera  Petaurus,  Phascogale,  Dasyurus  and  Perameles,  Hunter, 
on  the  contrary,  adopted  the  more  natural  and  philosophical  method  of  accurately 
pointing  out  the  differences  and  resemblances  of  each  species,  retaining  for  them, 
like  Adanson  with  reference  to  the  nondescripts  of  Senegal,  the  native  names, 
instead  of  applying  to  them  Linnaean  generic  appellatives,  which  could  only 
serve  to  propagate  erroneous  ideas  of  the  objects  to  which  they  were  attached. 
These  reflections  are  so  obviously  suggested  by  the  text,  that  the  following  is 
offered  as  an  apology  for  their  insertion:  the  writer  of  a volume  entitled  a 
“ Discourse  on  the  Study  of  Natural  History,”  which  by  some  unfortunate 
casually  has  appeared  in  the  same  series  of  publications  as  that  which  contains 
Herschel’s  admirable  Discourse  on  Natural  Philosophy,  introduces  the  name  of 
John  Hunter  in  his  account  of  the  naturalists  who  have  contributed  to  the  rise 
and  progress  of  zoology  for  the  sole  purpose  of  instituting  a disparaging  compari- 
son between  that  great  and  original  tbinker  and  the  author  of  the  General  Zoology. 
“ Dr.  Shaw,”  Mr.  Swainson  observes,  “ was  unquestionably  the  writer  of  nearly 
all  the  zoological  descriptions  in  White’s  Voyage  to  New  South  Wales,  whereas 
he  (John  Hunter)  merely  wrote  the  account  of  five  of  the  quadrupeds  and  these 
are  neither  named  nor  scientifically  characterized.” 

Now  the  fact  is  that  Hunter’s  descriptions  of  the  parts  best  adapted  for 
zoological  characters  are  so  exact  and  so  minute  that  a zoologist  has  no  difficulty 
in  assigning  the  species  to  the  most  recent  zoological  subdivisions,  as  any  one 
may  convince  himself  who  compares  the  account  of  the  Tapao  Tafa  with  the 
characters  assigned  by  Temminck  to  his  genua  Phascogale.  But  Hunter  added 
also  observations  on  tbe  differences  and  peculiarities  of  the  internal  structure  of 
the  marsupial  quadrupeds,  yet  Dr.  Shavv  was  so  blind  to  the  true  methods 
of  advancing  the  science  of  zoology,  and  so  little  able  to  appreciate  the  labours 
of  his  colleague  to  this  end,  that  science  was  deprived  of  the  benefit  of  Hunter’s 
anatomical  description  of  five  marsupial  genera^  because  they  were,  in  Dr.  Shaw’s 
estimation,  little  calculated  for  the  readers  of  a zoological  appendix!] 


472 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


some  species  of  one  tribe  partaking  of  similar  properties  with  a 
species  of  another  tribe. 


Of  ihe  Kangaroo* 

Tliis  animal  (probably  from  its  size)  was  the  principal  one  taken 
notice  of  in  this  island;  the  only  parts  at  first  brought  home  were 
some  skins  and  skulls,  and  I was  favoured  with  one  of  the  skulls 
from  Sir  Joseph  Banks.  As  the  teeth  of  such  animals  as  are  already 
known  in  some  degree  point  out  their  digestive  organs,  I was  in 
hopes  that  I might  have  been  able  to  form  an  opinion  of  the  parti- 
cular tribe  of  the  animals  already  known  to  which  the  kangaroo 
should  belong ; but  the  teeth  did  not  accord  with  those  of  any  one 
class  of  animals  I was  acquainted  with,  therefore  I was  obliged  to 
wait  with  patience  till  I could  get  the  whole;  and  in  many  of  its  other 
organs  the  deviation  from  other  animals  is  not  less  than  in  its  teeth. 
In  its  mode  of  propagation  it  very  probably  comes  nearer  to  the 
opossum  than  any  other  animal,  although  it  is  not  at  all  similar  to 
it  in  other  respects.  Its  hair  is  of  a grayish-brown  colour,  similar 
to  that  of  the  wild  rabbit  of  Great  Britain,  is  thick  and  long  when 
the  animal  is  old  ; but  it  is  late  in  growing,  and  when  only  begun 
to  grow  it  is  like  a strong  dowm ; however,  in  some  parts  it  begins 
earlier  than  others,  as  about  the  mouth,  &c.  In  all  the  young  kan- 
garoos yet  brought  home  (although  some  as  large  as  a full-grown 
rat)  they  have  all  the  marks  of  a foetus:  no  hair;  ears  lapped  close 
over  the  head  ; no  marks  on  the  feet  of  having  been  used  in 
progressive  motion : the  large  nail  on  the  great  toe  sharp  at  the 
point,  and  the  sides  of  the.,  mouth  united  something  like  the  eyelids 
of  a puppy  just  whelped,  having  only  a passage  at  the  anterior  part. 
This  union  of  the  two  lips  on  the  sides  is  of  a particular  structure  ; it 
wears  off  as  it  grows  up,  and  by  the  time  it  is  the  size  of  a small 
rabbit,  disappears. 

Of  the  Teeth  of  the  Kangaroo. 

The  teeth  of  this  animal  are  so  singular  that  it  is  impossible  from 
them  to  say  what  tribe  it  is  of.  There  is  a faint  mixture  in  them, 
corresponding  to  those  of  different  tribes  of  animals.  Take  the  mouth 
at  large,  respecting  the  situation  of  the  teeth,  it  w'ould  class  in  some 
degree  with  the  Scalpris  dentataf  in  a fainter  degree  with  the 
horse  and  ruminants;  and  with  regard  to  thelineof  direction  of  all 
the  teeth,  they  are  very  like  those  of  the  Scalpris  dentata.  The 
fore  teeth  in  the  upper  jaw  agree  with  the  hog,  and  those  in  the 
lower,  in  number,  with  the  Scalpris  dentata,  but  with  regard  to 

* [The  species  here  for  the  first  time  described  is  the  Macropus  major  of 
modern  systems:  several  other  species  of  the  same  genus  have  since  been  dis- 
covered.] 

t [This  tribe  includes  the  rat,  &c.  (it  corresponds  to  the  order  Glires  of  Linnseus 
and  the  Rodentia  of  Cuvier.)] 


DESCRIPTIONS  OF  SOME  ANIMALS,  ETC. 


473 


position,  and  probably  use,  with  the  hog.  The  grinders  would 
seem  to  be  a mixture  of  hog  and  ruminant,  the  enamel  on  their  ex- 
ternal and  grinding  surfaces  rather  formed  into  several  cutting 
edges  than  points.  There  are  six  incisors  in  the  upper  jaw  and 
only  two  in  the  lower,  but  these  two  are  so  placed  as  to  oppose 
those  of  the  upper  ; five  grinders  in  each  side  of  each  jaw,  the  most 
anterior  of  which  is  small.* 

The  proportions  of  some  of  the  parts  of  this  animal  bear  no 
analogy  to  what  is  common  in  most  others.  The  disproportions  in 
the  length  between  the  fore  legs  and  the  hind  are  very  considerable, 
also  in  their  strength,  yet  perhaps  not  more  than  in  the  jerboa. 
This  disproportion  between  the  fore  legs  and  the  hind  is  princi- 
pally in  the  more  adult ; for  in  the  very  young,  about  the  size  of  a 
half-grown  rat,  they  are  pretty  well  proportioned  ; which  shows 
that  at  the  early  period  of  life  they  do  not  use  progressive  motion.! 
The  proportions  of  the  different  parts  of  which  the  hind  legs  are 
composed  are  very  different.  The  thigh  of  the  kangaroo  is  ex- 
tremely short,  and  the  leg  is  very  long.  The  hind  foot  is  uncom- 
monly long,  on  which,  to  appearance,  are  placed  three  toes,  the 
middle  toe  by  much  the  largest  and  the  strongest,  and  looks  some- 
thing; like  the  long;  toe  of  an  ostrich.  The  outer  toe  is  next  in  size; 
and  what  appears  to  be  the  inner  toe,  is  two  inclosed  in  one  skin 
or  covering.  The  great  toe  nail  much  resembles  that  of  an  ostrich, 
as  also  the  nail  of  the  outer  toe;  and  the  inner,  which  appears  to 
be  but  one  toe,  has  two  small  nails,  which  arc  bent  and  sharp. J 

* [Hunter  appears  to  have  taken  this  description  from  a skull  in  which  the 
first  deciduous  molar  was  still  retained.  The  total  number  of  molares  which 
are  developed  in  the  jaws  of  a kanoraroo  are  seven  on  each  side  of  each  jaw  ; the 
greatest  number  in  use  at  any  given  time  is  four  on  each  side  of  each  jaw;  a 
posterior  or  fifth  molar  may  be  visible  above  the  socket  in  the  dry  skull,  but  it 
does  not  cut  the  gum  for  use  till  the  anterior  one  is  pushed  out. 

The  succession  of  the  molares  is  from  behind  forwards  in  both  jaws.  The 
first  deciduous  molar,  upper  jaw,  resembles  the  first  permanent  false  molar  in 
the  potoroo ; it  is  elongated,  com|)ressed,  and  traversed  by  a longitudinal  sharp 
middle  ridge,  at  the  internal  base  of  which  are  three  small  tubercles.  It  is  for 
cutting  rather  than  bruising.  The  corresponding  tooth,  lower  jaw,  is  similar  in 
form,  but  smaller,  and  has  one  tubercle  in  the  posterior  part  of  the  inner  side  of 
the  base.  In  some  species  of  kangaroo,  Macropus  degans,  the  false  molar 

is  permanent,  but  its  earlier  loss  in  Macr.  major  does  not  warrant  a generic  dis- 
tinction. The  second  deciduous  molar  has  the  form  of  the  ordinary  grinders, 
but  is  smaller  ; it  is  shed  before  the  first.  The  third  is  similar,  but  somewhat 
larger;  and  so  also  of  the  fourth:  this  grinder  is  much  worn  in  old  skulls,  and 
in  the  lower  jaw  is  lost,  leaving  then  only  ixi  molares  in  aged  individuals.  The 

fifth,  sixth,  and  seventh  follow  each  other  from  behind  forwards,  and  are  of 
equal  size. 

Before  the  fourth  grinder  is  in  place  the  permanent  incisores  are  gained  ; these 
closely  resemble  their  predecessors,  but  are  somewhat  larger.  In  the  Macropus 
major  the  exterior  incisor  upper  jaw  presents  two  inflected  folds  of  enamel ; 
these  are  wanting  in  the  corresponding  teeth  of  the  smaller  species,  which  retain 
the  spurious  molares.] 

f [At  a still  earlier  period  the  fore  legs,  following  the  usual  law  of  develop- 
ment, exceed  the  hind  tegs  in  length,] 

X [Each  of  these  toes  has  it  proper  metatarsal  and  phalano-eal  bones.] 

41^ 


474 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


From  the  heel  along  the  under  side  of  the  foot  and  toe,  the  skin  is 
adapted  for  walking  upon. 

The  fore  legs,  in  the  full-grown  kangaroo,  are  small  in  propor- 
tion to  the  hind,  or  the  size  of  the  animal ; the  feet,  or  hands,  are 
also  small.  The  skin  on  the  palm  is  different  from  that  on  the  back 
of  the  hand  and  fingers.  There  are  five  toes  or  fingers  on  this 
foot,  the  middle  rather  the  largest;  the  others  become  ver)'-  gradu- 
ally shorter,  and  are  all  nearly  of  the  same  shape.  The  nails  are 
sharp,  fit  for  holding.  The  tail  is  long  in  the  old,  but  not  so  long, 
in  proportion  to  the  size  of  the  animal,  in  the  young.  It  would 
seem  to  keep  pace  with  the  growth  of  the  hind  legs,  which  are  the 
instruments  of  progressive  motion  in  this  animal,  and  which  would 
also  show  that  the  tail  is  a kind  of  second  instrument  in  this  action.* 
The  under  lip  is  divided  in  the  middle,  each  side  rounded  off  at  the 
division.  It  has  two  clavicles,  but  they  are  short,  so  that  the  shoul- 
ders are  not  thrown  out. 


The  Poloroo  or  Kangaroo  Rat.^ 

The  head  is  flat  sideways,  but  not  so  much  so  as  in  the  true 
Scalpris  dentata.  The  ears  are  neither  long  nor  short,  but  much 
like  those  of  a mouse  in  proportion  to  the  size  of  the  animal. 

The  fore  legs  are  short  in  comparison  to  the  hind.  There  are 
four  toes  on  the  fore-fee1,J  the  two  middle  are  long,  and  nearly  of 
equal  lengths,  with  long  narrow  tails,  slightly  bent ; the  two  side 
toes  are  sliort,  and  nearly  equal  in  size,  but  the  outer  rather  the 


* [It  must  be  remembered  that  at  this  time  Hunter  had  never  seen  the  living- 
kangaroo,  but  the  numerous  opportunities  of  -w’itnessing  the  locomotion  of  this 
remarkable  animal  afforded  to  subsequent  observers  have  all  testified  to  the 
sagacity  of  his  provision  of  the  use  of  the  tail.] 

f [This  animal  differs  from  the  kangaroo  in  having  two  small  canines,  in  addi- 
tion to  the  six  incisors  in  the  upper  jaw.  The  first  compressed  or  false  molar 
on  each  side  of  each  jaw,  which  is  shed  in  the  great  kangaroo,  is  here  retained. 
The  first  incisors  of  the  upper  jaw  are  also  relatively  longer  and  more  curved. 
The  potoroo,  therefore,  forms  the  type  of  a distinct  genus,  which  was  named  by 
llliger  ‘ Hypsiprymnus,’ from  the  Greek  word  'T-{t7rfviAvo(,  signifying  the  hinder 
parts  raiseT  Of  this  genus  three  or  four  species  have  been  indicated.  The  skin 
and  cranium  of  the  individual  described  by  Hunter,  and  figured  in  the  Appendix  to 
White’s  Voyage,  are  preserved  in  the  Museum  of  the  College  of  Siirgeons.  The 
skull  agrees  in  size  and  form,  as  also  the  proportions  of  the  stuffed  skin,  with 
the  skeleton  of  the  Hypsiprymnus  murinus,  given  in  Pander  and  D’Alton’s 
‘ Skelete  da-  Beufelthiere,’’  tab.  iii. 

We  give  the  following  admeasurements  from  the  original  specimen : 

ft.  ill.  In. 

From  the  end  of  the  nose  to  the  vent  . . . 13  0 

Length  of  the  tail  .......  0 8 7^ 

Length  of  the  skull  . . . . . . 0 3 3 

Length  of  the  foot  . . . . . . 0 3 3 

d’he  Hypsiprymnus  murinus  of  llliger  is  the  Hypsiprymnus  TV/iite  of  Quoy  and 
Gaimard,  the  Macropus  minor  of  Shaw.] 

y [In  the  specimen  here  described,  as  in  the  rest  of  the  genus,  there  are  five 
toes  on  the  fore  foot,  but  the  fifth  is  so  small  as  scarcely  to  perform  any  part  of 
the  oflfice  of  a toe. 


DESCRIPTIONS  OF  SOME  ANIMALS,  ETC. 


475 


largest.  From  the  nails  on  the  two  middle  toes  one  would  suppose 
that  the  animal  burrowed.  Their  hind  legs  are  long,  and  it  is  in 
their  power  to  stand  either  on  the  w'hole  foot,  or  on  the  toes  only. 
On  the  hind  legs  are  three  toes,  the  middle  one  large,  and  the  two 
side  ones  short  ;*=  the  tail  is  long.  The  hair  on  the  body  is  rather 
thin  ; it  is  of  two  kinds,  a fur,  and  a long  hair,  which  last  becomes 
exterior  from  its  length.  The  fur  is  the  finest,  and  is  composed  of 
serpentine  hairs ; the  long  hair  is  stronger,  and  is  also  serpentine, 
for  more  than  two-thirds  of  its  length  near  to  the  skin,  and  termi- 
nates in  a pretty  strong  pointed  end,  like  the  quill  of  a hedgehog  ; 
it  is  of  a brownish-gray  colour,  something  like  the  brown  or  gray 
rabbit,  w'ith  a tinge  of  a gi’eenisli-yellow. 

It  has  a pouch  on  the  lower  part  of  the  belly  ; the  mouth  opens 
forwards,  and  the  cavity  extends  backwards  to  the  pubis,  where  it 
terminates;  on  the  abdominal  surface  of  this  pouch  are  four  nipples 
or  two  pair,  each  pair  placed  very  near  the  other.f 

The  Hepoona  i?oo.J 

This  animal  is  of  the  size  of  a small  rabbit ; it  has  a broad  flat 
body  ; the  head  agood  deal  resembles  that  of  the  squirrel ; theeyes  are 
full,  prominent,  and  large  ; the  ears  broad  and  thin  ; its  legs  short,  and 
its  tail  very  long.  Between  the  fore  and  hind  legs,  on  each  side, 
is  placed  a doubling  of  the  skin  of  the  side,  which,  when  the  legs 
are  extended  laterally,  is  as  it  were  pulled  out,  forming  a broad 
lateral  wing  or  fin,  and  when  the  legs  are  made  use  of  in  walking,  this 
skin,  by  its  elasticity,  is  drawn  close  to  the  side  of  the  animal,  and 
forms  a kind  of  ridge,  on  which  the  hair  has  a peculiar  appearance. 
In  this  respect  it  is  very  similar  to  the  flying  squirrel  of  America. 

It  has  five  toes,  on  each  fore  foot,  with  sharp  nails.  The  hind- 
foot  has  also  five  toes,  but  differs  considerably  from  the  fore-foot ; 
one  of  the  toes  may  be  called  a thumb,  having  a broad  nail,  some- 
thing like  that  of  the  monkey  or  opossum.  What  answers  to  the 
fore  and  middle  toes  are  united  in  one  common  covering,  and  ap- 
pear like  one  toe  with  two  nails  : this  is  somewhat  similar  to  the 
kangaroo.  The  two  other  toes  are  in  the  common  form  ; these 

* [There  are  four  toes  on  this  foot,  as  in  the  great  kangaroo,  but  the  two 
inner  ones  are  so  conjoined  by  a common  sheath  of  integument  as  to  act  as  but 
one.] 

t [The  genera  Macropus  and  Hypsiprymnus  are  principally  distinguished 
from  the  other  marsupialia  anatomically  b}^  having  a large  stomach,  complicated 
with  sacculi,  produced  as  in  the  colon,  by  being  puckered  upon  longitudinal 
bands.] 

X [This  animal  is  the  type  of  the  genus  Pteaurus,  which  is  characterized  by 
the  following  dental  formula  : incisors  molares  spuriae  molares  tubercu- 
lati  — = 34.  It  is  the  largest  known  species,  and  is  the  Pelaurus  Taguanoides 

4.4  ® * 

of  Desmarest,  and  the  Dldelphys  Peianrus  of  Shaw. 

The  original  specimen,  described  and  figured  in  White’s  Appendix,  is  pre- 
served in  the  Museum  of  the  Royal  College  of  Surgeons.] 


476 


HUNTER  ON  THE  ANIMAL  CECONOMY. 


lour  nails  are  sliarp,  like  those  on  the  fore  foot.  This  formation  of 
the  foot  is  well  calculated  for  holding  anything  while  it  is  moving 
its  body  or  its  fore  foot  to  other  parts  ; a property  belonging  (pro- 
bably) to  all  animals  which  move  from  the  hind  parts,  such  as  the 
monkey,  mocock,  mongoose,  opossum,  parrot,  leech,  &c.  Its  hair 
is  very  thick  and  long,  making  a very  fine  fur,  especially  on  the 
back.  It  is  of  a dark  brown-gray  on  the  upper  part,  a light  w'hite 
gray  on  the  lower  side  of  what  may  be  termed  the  wing,  and 
white  on  the  under  surface,  from  the  neck  to  the  parts  adjacent 
to  the  anus. 


TVlia  Tapoua  Roo.^ 

This  animal  is  about  the  size  of  a racoon,  is  of  a dark  gray 
colour  on  the  back,  becoming  rather  lighter  on  the  sides,  which 
terminates  in  a rich  brown  on  the  belly.  The  hair  is  of  two  kinds, 
a long  hair  and  a kind  of  fur,  and  even  the  long  hair  at  the  roots  is 
of  the  fur  kind.  The  head  is  short,  the  eyes  rather  prominent; 
the  ears  broad,  not  peaked.  The  teeth  resemble  those  of  all  the 
animals  from  that  country  I have  hitherto  seen.  The  incisors  are 
not  continued  into  the  grinders  by  intermediate  teeth,  although  there 
are  two  teeth  in  the  intermediate  space  in  the  upper  jaw,  and  one 
in  the  lower.  The  incisors  are  similar  to  those  of  the  kangaroo, 
and  six  in  number  in  the  u|'per  jaw,  opposed  by  two  in  the  lower, 
which  have  an  oblique  surface  extending  some  distance  from  their 
edge,  so  as  to  increase  the  surface  of  contact.  There  are  two 
cuspidati  on  each  side  in  the  upper  jaw,  and  only  one  in  the 
lowmr;  five  grinders  on  each  side  of  each  jaw,  the  first  rather  pointed, 
the  others  appear  nearly  of  the  same  size,  and  quadrangular  in 
their  shape,  with  a hollow  running  across  their  base  from  the  out- 
side to  the  inner,  which  is  of  some  depth ; and  another  which 
crosses  it,  but  not  so  deep,  dividing  the  grinding  surface  into  four 
points.  On  the  fore  foot  there  aie  five  toes,  the  inner  the  shortest, 
resembling,  in  a slight  degree,  a thumb.  The  hind  foot  resembles 
a hand,  or  that  of  the  monkey  and  opossum,  the  great  toe  having 
no  nail,  and  opposing  the  whole  sole  of  the  foot,  which  is  bare. 
The  nails  on  the  other  toes,  both  of  the  fore  and  hind  foot,  resemble 
in  a small  degree  those  of  the  cat,  being  broad  and  covered  ; and 
the  last  bone  of  the  toe  has  a projection  on  the  under  side,  at  the 
articulation.  Each  nail  lias,  in  some  degree,  a small  sheath, 
covering  its  base  when  drawn  up.t  The  tail  is  long,  covered  with 

* [This  species  is  now  calied  the  vnipine  opossum,  or  vulpine  phalanger 
(^Phalangisia  Vulpina^')  and  is  the  type  of  a genus  of  which  the  species  are  not 
confined  to  Australia,  but  some  were  known,  as  inhabitants  of  the  Indian  isles, 
to  the  older  naturalists.  The  dental  characters  are  described  in  the  text.] 

f [In  the  hinder  foot  the  two  toes  next  the  thumb  are  inclosed  in  a common 
sheath  of  integument  as  far  as  the  ungual  phalanx  : this  is  the  commencement  of 
that  peculiar  degradation  of  the  second  and  middle  toe  which  is  carried  to  so 
great  an  extreme  in  the  kangaroos  and  potoroos.  The  term  F/ialangisla  was 
given  to  the  genus  in  question  in  consequence  of  this  binding  together  of  the 
phalanges  of  two  of  the  toes  in  the  hind  feet.] 


DESCRIPTIONS  OF  SOME  ANIMALS,  ETC. 


477 


long  hair,  except  the  under  surface  of  that  half  towards  the  termi- 
nation, of  the  breadth  of  half  an  inch,  becoming  broader  near  the 
tip  or  termination  : this  surface  is  covered  with  a strong  cuticle, 
and  is  adapted  for  laying  hold. 


The  Tapoa  Tafa,  or  Tapha* 

This  animal  is  the  size  of  a rat,  and  has  very  much  the  appear- 
ance of  the  martin  cat,  but  hardly  so  long  in  the  body  in  proportion 
to  its  size.  The  head  is  flat  forwards,  and  broad  from  side  to  side, 
especially  between  the  eyes  and  ears ; the  nose  is  peaked,  and  pro- 
jecting beyond  the  teeth,  which  makes  the  upper  jaw  appear  to  be 
considerably  longer  than  the  lower;  the  eyes  are  pretty  large;  the 
ears  are  broad  especially  at  their  base,  not  becoming  regularly  nar- 
rower to  a pointjf  nor  with  a very  smooth  edge,  and  having  a small 
process  on  the  concave  or  inner  surface,  near  to  the  base.  It  has 
long  whiskers  from  the  sides  of  the  cheeks,  which  begin  forwards, 
near  the  nose,  by  small  and  short  hairs,  and  become  longer  and 
stronger  as  they  approach  the  eyes.J  It  has  veiy  much  the  hair 
of  a rat,  to  which  it  is  similar  in  colour;  but  near  to  the  setting  on 
of  the  tail  it  is  of  a lighter  brown,  forming  a broad  ring  round  it. 
The  fore  feet  are  shorter  than  the  hind,  but  much  in  the  same  pro- 
portion as  those  of  the  rat;  the  hind  feet  are  m.ore  flexible.  There 
are  five  toes  on  the  fore  feet,  the  middle  the  largest,  falling  off  on 
each  side  nearly  equally ; but  the  fore  or  inner  toe  is  rather  shortest ; 
they  are  thin  from  side  to  side;  the  nails  are  pretty  broad,  laterally, 
and  thin  at  their  base;  not  very  long,  but  sharp:  the  animal  walks 
on  its  whole  palm,  on  which  there  is  no  hair.  The  hind  feet  are 
pretty  long,  and  have  five  toes;  that  which  answers  to  our  great 
toe  is  very  short,  and  has  no  nail ; the  next  is  the  longest  in  the 
whole,  falling  gradually  ofT  to  the  outer  toe  ; the  shape  of  the  hind 
toes  is  the  same  as  in  the  fore  feet,  as  are  likewise  the  nails  ; it 
walks  nearly  on  the  whole  foot.  The  tail  is  long,  and  covered  with 
long  hair,  but  not  all  of  the  same  colour.  The  teeth  of  this  creature 
are  different  from  any  other  animal  yet  known.  The  mouth  is  full 
of  teeth  ; the  lower  jaw  narrow,  in  comparison  to  the  upper,  more 
especially  backwards,  which  allows  of  much  broader  grinders  in 
this  jaw  than  in  the  lower,  and  which  occasions  the  grinders  in  the 
upper  jaw  to  project  considerably  over  those  in  the  lower.  In  the 
middle  the  cuspidaii  oppose  one  another ; the  upper  piercers  or 
holders  go  behind  those  of  the  lower;  the  second  class  of  incisors 
in  the  lower  jaw  overtop  those  of  the  upper,  while  the  two  first  in 
the  lower  go  within,  or  behind  those  of  the  upper.  In  the  upper 

* [This  animal  is  the  Phascogah  penicillafa  of  Temminck,  {Munographies  dt 
Mammalogie,  p.  58.),  Dasyurus  2'afa  of  Geoffroy,  Didelphis  penicillata  of  Shaw.] 

t [Temminek  describes  the  ears  of  Phascogale  penicillata  as  being  “ arrondies 
par  le  haut.” — Loc.  cit.,  p.  59.] 

± [“  Les  moustaches  des  levres  sont  places  plus  pres  des  yeux  que  de  nez.” — 
3id.} 


478 


HUNTER  ON  THE  ANIMAL  O3C0N0MY. 


jaw,  before  the  holders  ‘ (canines)’,  there  are  four  teeth  ‘ (incisors)’ 
on  each  side,  three  of  which  are  pointed,  the  point  standing  on 
tlie  inner  surface ; and  the  two  in  front  are  longer,  standing  more 
obliquely  forwards,  and  appear  to  be  appropriated  for  a particular 
use.* 

The  holders  ‘ (canines)’  are  a little  way  behind  the  last  fore  teeth, 
to  allow  those  of  the  lower  jaw  to  come  between  ; they  are  pretty 
long. 

The  cuspidati  (spurious  molares)  on  each  side  become  longer  and 
larger  towards  the  grinders  (true  molares) ; they  are  points  or  cones 
placed  on  a broad  base. 

There  are  four  grinders  on  each  side,  the  middle  two  the  largest, 
the  last  the  least;  their  base  is  a triangle,  of  the  scalenus  kind,  or 
having  one  angle  obtuse  and  two  acute.  Their  base  is  composed 
of  two  surfaces,  an  inner  and  an  outer,  divided  by  processes  or 
points;  it  is  the  inner  that  the  grinders  of  the  lower  jaw  oppose, 
when  the  mouth  is  regularly  shut. 

The  lower  jaw  has  three  fore  teeth,  or  incisors,  on  each  side,  the 
first  considerably  the  largest,  projecting  obliquely  forwards:  the 
other  two  of  the  same  kind,  but  smaller;  the  last  the  smallest. 

The  holder  (canine)  in  this  jaw  is  not  so  large  as  in  the  upper  jaw, 
and  close  to  the  incisors. 

There  are  three  cuspidati  ‘ (false  molares), f the  middle  one  the 
largest,  the  last  the  least:  these  are  cones  standing  on  their  base, 
but  not  on  the  middle,  rather  on  the  anterior  side. 

There  arc  four  grinders,  the  two  middle  the  largest,  and  rather 
quadrangular,  each  of  which  has  a high  point  or  cone  on  the 
outer  edge,  with  a smaller,  and  three  more  diminutive  on  the  inner 
edge. 

It  is  impossible  to  say  critically  what  the  various  forms  of  these 
teeth  are  adapted  for,  from  the  general  principles  of  teeth.  In  the 

* [This  superiority  of  size  of  the  two  middle  incisors  of  the  two  jaws  is  one 
of  the  characters  which  distinguish  Phascogale  from  Dasyurus.~\ 

f [Tliis  is  the  second  and  most  decisive  distinguishing  generic  character 
between  Phascogale  and  Dasyurus,  the  latter  having  only  two  false  molars  on 
each  side  of  each  jaw,  instead  of  three.  Had  Fischer,  Lesson,  and  other  zoologists 
compared  the  description  of  the  teeth  in  the  text  with  that  given  by  Temminck 
in  his  Monographies  de  Marnmalogie,tis  characterizing  his  genus  Phascogale,  they 
could  not  have  hesitated  to  refer  the  Tapoa  tafa  of  Hunter  to  that  genus,  and  the 
catalogues  of  mammalia  need  not  have  contained  the  imaginary  species  Dasyurus 
Tafa,  which  M.  Temminck  observes  “ n’a  point  ete  vue  depuis  par  aucun 
naturaliste,”  and  which  species  Lesson  suspects  to  be  founded  on  the  immature 
state  of  the  spotted  Dasyure  (Dasyurus  viverrinus).  But  neither  observation  nor 
analogy  fa.vour  the  idea  of  spots  being  acquired  by  age ; on  the  contrary,  the 
examples  of  the  lion  and  the  puma,  which  are  spotted  only  when''young,  show 
that  they  are  more  likely  to  be  lost. 

In  the  Hunterian  collection  the  posterior  half  of  the  body  of  the  individual 
described  by  Hunter  is  preserved,  to  show  the  marsupium  and  teats;  these  are 
eight  in  number,  and  arranged  in  a circle.  The  tail  perfectly  corresponds  with 
the  specimens  of  Phascogale  penicillata,  and  with  M.  Temminck’s  description, 
being  “ couverte  de  poils  assez  courts  a la  base,  tres-long,  raides,  et  en  pinceaii 
vers  la  pointe”  (foe.  cit,,  p.  59) ; and  the  long  hairs  are  black.] 


DESCRIPTIONS  OF  SOME  ANIMALS,  ETC. 


479 


front  we  have  what  may  divide  and  tear  off ; behind  those  there 
are  holders  or  destroyers  ; behind  the  latter,  such  as  will  assist  in 
mashing,  as  the  grinders  of  the  lion,  and  other  carnivorous  animals ; 
and  last  of  all,  grinders,  to  divide  parts  into  smaller  portions,  as  in 
the  graminivorous  tribe  ; the  articulation  of  the  jaw,  in  some  degree, 
admits  of  all  those  motions. 

A Dingo,  or  Dog  of  JVew  South  Wales. 

This  animal  is  a variety  of  the  dog,  and,  like  the  shepherd’s  dog 
in  most  countries,  approaciies  near  to  the  original  of  the  species, 
which  is  the  w'olf;  but  is  not  so  large,  and  does  not  stand  so  high 
on  its  legs.  The  ears  are  short  and  erect,  the  tail  rather  bushy; 
the  hair,  which  is  of  a reddish-dun  colour,  is  long  and  thick,  but 
straight.  It  is  capable  of  barking,  although  not  so  readily  as  the 
European  dog,  is  very  ill-natured  and  vicious,  and  snarls,  howls 
and  moans  like  dogs  in  common.  Whether  this  is  the  only  dog  in 
New  South  Wales,  and  whether  they  have  it  in  a wild  state,  is  not 
mentioned,  but  I should  be  inclined  to  believe  they  had  no  other,  in 
which  case  it  wilt  constitute  the  wolf  of  that  country ; and  that 
which  is  domesticated  is  only  the  wild  dog  tamed,  without  having 
yet  produced  a variety,  as  in  some  parts  of  America. 


THE  END. 


MV  J 


I 

Hunter 


